mm/mremap: 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/mremap.c

@@ -401,7 +401,7 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
 	unsigned long charged = 0;
 	unsigned long map_flags;
 
-	if (new_addr & ~PAGE_MASK)
+	if (offset_in_page(new_addr))
 		goto out;
 
 	if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len)
@@ -435,11 +435,11 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
 	ret = get_unmapped_area(vma->vm_file, new_addr, new_len, vma->vm_pgoff +
 				((addr - vma->vm_start) >> PAGE_SHIFT),
 				map_flags);
-	if (ret & ~PAGE_MASK)
+	if (offset_in_page(ret))
 		goto out1;
 
 	ret = move_vma(vma, addr, old_len, new_len, new_addr, locked);
-	if (!(ret & ~PAGE_MASK))
+	if (!(offset_in_page(ret)))
 		goto out;
 out1:
 	vm_unacct_memory(charged);
@@ -484,7 +484,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 	if (flags & MREMAP_FIXED && !(flags & MREMAP_MAYMOVE))
 		return ret;
 
-	if (addr & ~PAGE_MASK)
+	if (offset_in_page(addr))
 		return ret;
 
 	old_len = PAGE_ALIGN(old_len);
@@ -566,7 +566,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 					vma->vm_pgoff +
 					((addr - vma->vm_start) >> PAGE_SHIFT),
 					map_flags);
-		if (new_addr & ~PAGE_MASK) {
+		if (offset_in_page(new_addr)) {
 			ret = new_addr;
 			goto out;
 		}
@@ -574,7 +574,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 		ret = move_vma(vma, addr, old_len, new_len, new_addr, &locked);
 	}
 out:
-	if (ret & ~PAGE_MASK) {
+	if (offset_in_page(ret)) {
 		vm_unacct_memory(charged);
 		locked = 0;
 	}