autofs: don't fail to free_dev_ioctl(param)

Returning -ENOTTY here fails to free dynamically allocated param.

Link: http://lkml.kernel.org/r/20160812024815.12352.69153.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/autofs4/dev-ioctl.c

@@ -662,7 +662,8 @@ static int _autofs_dev_ioctl(unsigned int command,
 	fn = lookup_dev_ioctl(cmd);
 	if (!fn) {
 		pr_warn("unknown command 0x%08x\n", command);
-		return -ENOTTY;
+		err = -ENOTTY;
+		goto out;
 	}
 
 	fp = NULL;