linux/mm.h: canonicalize macro PAGE_ALIGNED() definition

The macro PAGE_ALIGNED() is prone to cause error because it doesn't
follow convention to parenthesize parameter @addr within macro body, for
example unsigned long *ptr = kmalloc(...); PAGE_ALIGNED(ptr + 16); for
the left parameter of macro IS_ALIGNED(), (unsigned long)(ptr + 16) is
desired but the actual one is (unsigned long)ptr + 16.

It is fixed by simply canonicalizing macro PAGE_ALIGNED() definition.

Link: http://lkml.kernel.org/r/57EA6AE7.7090807@zoho.com
Signed-off-by: zijun_hu <zijun_hu@htc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/mm.h

@@ -126,7 +126,7 @@ extern int overcommit_kbytes_handler(struct ctl_table *, int, void __user *,
 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
 
 /* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
-#define PAGE_ALIGNED(addr)	IS_ALIGNED((unsigned long)addr, PAGE_SIZE)
+#define PAGE_ALIGNED(addr)	IS_ALIGNED((unsigned long)(addr), PAGE_SIZE)
 
 /*
  * Linux kernel virtual memory manager primitives.