vfs: spread struct mount - __lookup_mnt() result

switch __lookup_mnt() to returning struct mount *; callers adjusted.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/mount.h b/fs/mount.h
index 47da816..44e5b6f 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -13,3 +13,5 @@
 {
 	return mnt != mnt->mnt_parent;
 }
+
+extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);