drm_hwcomposer: Replace LOG_TAG with drmhwc

It's a pain to use logcat filters for drm_hwcomposer since each file has a different tag necessitating one to specify each tag for the logcat filter or use a regex.

Use one tag for all of drm_hwcomposer to simplify this.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
diff --git a/backend/BackendManager.cpp b/backend/BackendManager.cpp
index 4e2532a..23fe270 100644
--- a/backend/BackendManager.cpp
+++ b/backend/BackendManager.cpp
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#define LOG_TAG "hwc-backend"
+#define LOG_TAG "drmhwc"
 
 #include "BackendManager.h"