Staging: line6: workaround for null pointer bug

Signed-off-by: Markus Grabner <grabner@icg.tugraz.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/line6/capture.c

@@ -147,6 +147,9 @@ void line6_capture_copy(struct snd_line6_pcm *line6pcm, char *fbuf, int fsize)
 	const int bytes_per_frame = line6pcm->properties->bytes_per_frame;
 	int frames = fsize / bytes_per_frame;
 
+	if (runtime == 0)
+		return;
+
 	if (line6pcm->pos_in_done + frames > runtime->buffer_size) {
 		/*
 		   The transferred area goes over buffer boundary,

drivers/staging/line6/revision.h

@@ -1,4 +1,4 @@
 #ifndef DRIVER_REVISION
 /* current subversion revision */
-#define DRIVER_REVISION " (revision 684)"
+#define DRIVER_REVISION " (revision 690)"
 #endif