drm_hwcomposer: Don't try to get configs for a disconnected connector

Short circuit getting the configs for connectors which are disconnected.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Change-Id: Ieabbf08f4d4a6c8b03f948399113e3ad04a2d93a
diff --git a/hwcomposer.cpp b/hwcomposer.cpp
index b6df190..ecbcd29 100644
--- a/hwcomposer.cpp
+++ b/hwcomposer.cpp
@@ -721,8 +721,15 @@
 		return -ENODEV;
 	}
 
-	if (hd->configs)
+	if (hd->configs) {
 		free(hd->configs);
+		hd->configs = NULL;
+	}
+
+	if (c->connection == DRM_MODE_DISCONNECTED) {
+		ret = -ENODEV;
+		goto out;
+	}
 
 	hd->configs = (drmModeModeInfoPtr)calloc(c->count_modes,
 					sizeof(*hd->configs));