Revert "rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation"

This reverts commit d3716f18a7d841565c930efde30737a3557eee69.

vmalloc cannot be used in BH disabled contexts, even
with GFP_ATOMIC.  And we certainly want to support
rhashtable users inserting entries with software
interrupts disabled.

Signed-off-by: David S. Miller <davem@davemloft.net>

lib/rhashtable.c

@@ -120,9 +120,8 @@ static struct bucket_table *bucket_table_alloc(struct rhashtable *ht,
 	if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER) ||
 	    gfp != GFP_KERNEL)
 		tbl = kzalloc(size, gfp | __GFP_NOWARN | __GFP_NORETRY);
-	if (tbl == NULL)
-		tbl = __vmalloc(size, gfp | __GFP_HIGHMEM | __GFP_ZERO,
-				PAGE_KERNEL);
+	if (tbl == NULL && gfp == GFP_KERNEL)
+		tbl = vzalloc(size);
 	if (tbl == NULL)
 		return NULL;