arm64: partially revert "ARM: 8167/1: extend the reserved memory for initrd to be page aligned"

This patch partially reverts commit 421520ba98290a73b35b7644e877a48f18e06004
(only the arm64 part). There is no guarantee that the boot-loader places other
images like dtb in a different page than initrd start/end, especially when the
kernel is built with 64KB pages. When this happens, such pages must not be
freed. The free_reserved_area() already takes care of rounding up "start" and
rounding down "end" to avoid freeing partially used pages.

Cc: <stable@vger.kernel.org> # 3.17+
Reported-by: Peter Maydell <Peter.Maydell@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm64/mm/init.c

@@ -335,14 +335,8 @@ static int keep_initrd;
 
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
-	if (!keep_initrd) {
-		if (start == initrd_start)
-			start = round_down(start, PAGE_SIZE);
-		if (end == initrd_end)
-			end = round_up(end, PAGE_SIZE);
-
+	if (!keep_initrd)
 		free_reserved_area((void *)start, (void *)end, 0, "initrd");
-	}
 }
 
 static int __init keepinitrd_setup(char *__unused)