compositor-drm: Write a name in the mode generated from a modeline

The current behaviour leaves the name empty, making it somewhat harder
to determine the characteristics of this mode from a debugger.

Signed-off-by: Emmanuel Gil Peyrot <emmanuel.peyrot@collabora.com>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>
[Pekka: wrap long line (ybakos)]
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

src/compositor-drm.c

@@ -2116,6 +2116,9 @@ parse_modeline(const char *s, drmModeModeInfo *mode)
 	else
 		return -1;
 
+	snprintf(mode->name, sizeof mode->name, "%dx%d@%.3f",
+		 mode->hdisplay, mode->vdisplay, fclock);
+
 	return 0;
 }