mm/msync: use vma_find() instead of vma linked list

Remove a single use of the vma linked list in preparation for the
removal of the linked list.  Uses find_vma() to get the next element.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Alexandre Frade <kernel@xanmod.org>

mm/msync.c

@@ -104,7 +104,7 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
 				error = 0;
 				goto out_unlock;
 			}
-			vma = vma->vm_next;
+			vma = find_vma(mm, vma->vm_end);
 		}
 	}
 out_unlock: