powerpc/mm: Unindent htab_dt_scan_page_sizes()

We can unindent the bulk of htab_dt_scan_page_sizes() by returning early
if the property is not found. That is nice in and of itself, but also
has the advantage of making it clear that we always return success once
we have found the ibm,segment-page-sizes property.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/hash_utils_64.c

@@ -334,70 +334,69 @@ static int __init htab_dt_scan_page_sizes(unsigned long node,
 		return 0;
 
 	prop = of_get_flat_dt_prop(node, "ibm,segment-page-sizes", &size);
-	if (prop != NULL) {
-		pr_info("Page sizes from device-tree:\n");
-		size /= 4;
-		cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
-		while(size > 0) {
-			unsigned int base_shift = be32_to_cpu(prop[0]);
-			unsigned int slbenc = be32_to_cpu(prop[1]);
-			unsigned int lpnum = be32_to_cpu(prop[2]);
-			struct mmu_psize_def *def;
-			int idx, base_idx;
-
-			size -= 3; prop += 3;
-			base_idx = get_idx_from_shift(base_shift);
-			if (base_idx < 0) {
-				/*
-				 * skip the pte encoding also
-				 */
-				prop += lpnum * 2; size -= lpnum * 2;
+	if (!prop)
+		return 0;
+
+	pr_info("Page sizes from device-tree:\n");
+	size /= 4;
+	cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
+	while(size > 0) {
+		unsigned int base_shift = be32_to_cpu(prop[0]);
+		unsigned int slbenc = be32_to_cpu(prop[1]);
+		unsigned int lpnum = be32_to_cpu(prop[2]);
+		struct mmu_psize_def *def;
+		int idx, base_idx;
+
+		size -= 3; prop += 3;
+		base_idx = get_idx_from_shift(base_shift);
+		if (base_idx < 0) {
+			/* skip the pte encoding also */
+			prop += lpnum * 2; size -= lpnum * 2;
+			continue;
+		}
+		def = &mmu_psize_defs[base_idx];
+		if (base_idx == MMU_PAGE_16M)
+			cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
+
+		def->shift = base_shift;
+		if (base_shift <= 23)
+			def->avpnm = 0;
+		else
+			def->avpnm = (1 << (base_shift - 23)) - 1;
+		def->sllp = slbenc;
+		/*
+		 * We don't know for sure what's up with tlbiel, so
+		 * for now we only set it for 4K and 64K pages
+		 */
+		if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K)
+			def->tlbiel = 1;
+		else
+			def->tlbiel = 0;
+
+		while (size > 0 && lpnum) {
+			unsigned int shift = be32_to_cpu(prop[0]);
+			int penc  = be32_to_cpu(prop[1]);
+
+			prop += 2; size -= 2;
+			lpnum--;
+
+			idx = get_idx_from_shift(shift);
+			if (idx < 0)
 				continue;
-			}
-			def = &mmu_psize_defs[base_idx];
-			if (base_idx == MMU_PAGE_16M)
-				cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
-
-			def->shift = base_shift;
-			if (base_shift <= 23)
-				def->avpnm = 0;
-			else
-				def->avpnm = (1 << (base_shift - 23)) - 1;
-			def->sllp = slbenc;
-			/*
-			 * We don't know for sure what's up with tlbiel, so
-			 * for now we only set it for 4K and 64K pages
-			 */
-			if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K)
-				def->tlbiel = 1;
-			else
-				def->tlbiel = 0;
-
-			while (size > 0 && lpnum) {
-				unsigned int shift = be32_to_cpu(prop[0]);
-				int penc  = be32_to_cpu(prop[1]);
-
-				prop += 2; size -= 2;
-				lpnum--;
-
-				idx = get_idx_from_shift(shift);
-				if (idx < 0)
-					continue;
-
-				if (penc == -1)
-					pr_err("Invalid penc for base_shift=%d "
-					       "shift=%d\n", base_shift, shift);
-
-				def->penc[idx] = penc;
-				pr_info("base_shift=%d: shift=%d, sllp=0x%04lx,"
-					" avpnm=0x%08lx, tlbiel=%d, penc=%d\n",
-					base_shift, shift, def->sllp,
-					def->avpnm, def->tlbiel, def->penc[idx]);
-			}
+
+			if (penc == -1)
+				pr_err("Invalid penc for base_shift=%d "
+				       "shift=%d\n", base_shift, shift);
+
+			def->penc[idx] = penc;
+			pr_info("base_shift=%d: shift=%d, sllp=0x%04lx,"
+				" avpnm=0x%08lx, tlbiel=%d, penc=%d\n",
+				base_shift, shift, def->sllp,
+				def->avpnm, def->tlbiel, def->penc[idx]);
 		}
-		return 1;
 	}
-	return 0;
+
+	return 1;
 }
 
 #ifdef CONFIG_HUGETLB_PAGE