video: fix missing directory on video capture

if photo was taken before, then temporary directory in tmpfs was clean
and removed after all files were processed. Internal burst_dir
variable contains old value for directory, that doesn't exist anymore.

Let's create new temporary directory, when video recording is started.

src/process_pipeline.c

@@ -921,6 +921,7 @@ on_movie_start(void)
 
 	movie_recording = 1;
 	printf("movie recording on\n");
+	setup_capture();
 	spawn_movie("start");
 }