vfs: misc struct path constification

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/statfs.c b/fs/statfs.c
index 083dc0a..13ae259 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -63,7 +63,7 @@ static int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf)
 	return retval;
 }
 
-int vfs_statfs(struct path *path, struct kstatfs *buf)
+int vfs_statfs(const struct path *path, struct kstatfs *buf)
 {
 	int error;