qstr: constify instances in autofs4

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 631f155..432b0d5 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -225,7 +225,7 @@
 }
 
 static struct autofs_wait_queue *
-autofs4_find_wait(struct autofs_sb_info *sbi, struct qstr *qstr)
+autofs4_find_wait(struct autofs_sb_info *sbi, const struct qstr *qstr)
 {
 	struct autofs_wait_queue *wq;
 
@@ -249,7 +249,7 @@
  */
 static int validate_request(struct autofs_wait_queue **wait,
 			    struct autofs_sb_info *sbi,
-			    struct qstr *qstr,
+			    const struct qstr *qstr,
 			    struct dentry *dentry, enum autofs_notify notify)
 {
 	struct autofs_wait_queue *wq;