switch lookup_mnt()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 9797800..72ce2ae 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -370,7 +370,7 @@
 	return dentry->d_mounted;
 }
 
-extern struct vfsmount *lookup_mnt(struct vfsmount *, struct dentry *);
+extern struct vfsmount *lookup_mnt(struct path *);
 extern struct dentry *lookup_create(struct nameidata *nd, int is_dir);
 
 extern int sysctl_vfs_cache_pressure;