x11grab: Drop a spurious space in the extension reporting message

Signed-off-by: Diego Biurrun <diego@biurrun.de>

libavdevice/x11grab.c

@@ -223,7 +223,7 @@ static int x11grab_read_header(AVFormatContext *s1)
 
     use_shm = XShmQueryExtension(dpy);
     av_log(s1, AV_LOG_INFO,
-           "shared memory extension %s found\n", use_shm ? "" : "not");
+           "shared memory extension %sfound\n", use_shm ? "" : "not ");
 
     if (use_shm) {
         int scr = XDefaultScreen(dpy);