mm/mincore: use offset_in_page macro

linux/mm.h provides offset_in_page() macro.  Let's use already predefined
macro instead of (addr & ~PAGE_MASK).
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mincore.c

@@ -234,7 +234,7 @@ SYSCALL_DEFINE3(mincore, unsigned long, start, size_t, len,
 
 	/* This also avoids any overflows on PAGE_CACHE_ALIGN */
 	pages = len >> PAGE_SHIFT;
-	pages += (len & ~PAGE_MASK) != 0;
+	pages += (offset_in_page(len)) != 0;
 
 	if (!access_ok(VERIFY_WRITE, vec, pages))
 		return -EFAULT;