video(1) munmap fix

[Marcus Glocker]

Just try to unmap a buffer when something has been mapped before.

ok?


Index: video.c
===================================================================
RCS file: /cvs/xenocara/app/video/video.c,v
retrieving revision 1.14
diff -u -p -u -p -r1.14 video.c
--- video.c     31 May 2016 08:45:14 -0000      1.14
+++ video.c     2 Jun 2016 06:50:30 -0000
@@ -1313,7 +1313,8 @@ mmap_stop(struct video *vid)
 
        /* unmap the buffers */
        for (i = 0; i < MMAP_NUM_BUFS; i++) {
-               r = munmap(vid->mmap_buffer[i], vid->bpf);
+               if (vid->mmap_buffer[i] != NULL)
+                       r = munmap(vid->mmap_buffer[i], vid->bpf);
                if (r == -1) {
                        warn("munmap");
                        return 0;