Adding better error behavior to RS

Change-Id: Iea1cc76793f8978d60575404d7b1c5145e268d6e
diff --git a/libs/rs/driver/rsdProgramRaster.cpp b/libs/rs/driver/rsdProgramRaster.cpp
index b493759..9b64fa9 100644
--- a/libs/rs/driver/rsdProgramRaster.cpp
+++ b/libs/rs/driver/rsdProgramRaster.cpp
@@ -45,6 +45,9 @@
         case RS_CULL_NONE:
             RSD_CALL_GL(glDisable, GL_CULL_FACE);
             break;
+        default:
+            LOGE("Invalid cull type");
+            break;
     }
 
 }