devtmpfs: unlock mutex in case of string allocation error

Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 278371c..090dd48 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -101,8 +101,10 @@
 
 		/* parent directories do not exist, create them */
 		path = kstrdup(nodepath, GFP_KERNEL);
-		if (!path)
-			return -ENOMEM;
+		if (!path) {
+			err = -ENOMEM;
+			goto out;
+		}
 		s = path;
 		for (;;) {
 			s = strchr(s, '/');
@@ -117,6 +119,7 @@
 		}
 		kfree(path);
 	}
+out:
 	mutex_unlock(&dirlock);
 	return err;
 }