ANDROID: userfaultfd: adjust MOVE ioctl mode to confirm anon_vma removal

With anon_vma write-lock in the MOVE ioctl we observed several janky
interactions. Recent patches upstream patches resolve the issue [1].

[1] https://lore.kernel.org/all/20250923071019.775806-1-lokeshgidra@google.com/

Bug: 422561794
Change-Id: I2237ddcc12362aed2ebf7f1b3141f71863fef95f
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>

include/uapi/linux/userfaultfd.h

diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index dfac99e..835294fd 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -330,8 +330,10 @@ struct uffdio_move {
 	 * in swap-cache. Also, to avoid livelock when multiple threads try
 	 * to move same src folio. It's a KMI workaround and cannot be relied
 	 * upon by userspace.
+	 *
+	 * 61: confirm if anon_vma lock has been removed from MOVE ioctl.
 	 */
-#define UFFDIO_MOVE_MODE_CONFIRM_FIXED		((__u64)1<<62)
+#define UFFDIO_MOVE_MODE_CONFIRM_FIXED		((__u64)1<<61)
 	__u64 mode;
 	/*
 	 * "move" is written by the ioctl and must be at the end: the