mm/mremap:: use vma_lookup() instead of find_vma()

Using vma_lookup() verifies the address is contained in the found vma.
This results in easier to read code.

Link: https://lkml.kernel.org/r/20220312083118.48284-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mremap.c

@@ -942,8 +942,8 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 
 	if (mmap_write_lock_killable(current->mm))
 		return -EINTR;
-	vma = find_vma(mm, addr);
+	vma = vma_lookup(mm, addr);
-	if (!vma || vma->vm_start > addr) {
+	if (!vma) {
 		ret = EFAULT;
 		goto out;
 	}