display: Fix warnings

Treat warnings as errors again

Change-Id: Ibd7f484d31ad420b85e82fd5183d70bf7dce4bfa
diff --git a/liboverlay/overlayUtils.cpp b/liboverlay/overlayUtils.cpp
index f9ee326..cbd52ae 100644
--- a/liboverlay/overlayUtils.cpp
+++ b/liboverlay/overlayUtils.cpp
@@ -272,7 +272,7 @@
     if((int)verDscale)
         vertDeci = (uint8_t)log2f(verDscale);
 
-    if(src_w > mdpHw.getMaxMixerWidth()) {
+    if(src_w > (int) mdpHw.getMaxMixerWidth()) {
         //If the client sends us something > what a layer mixer supports
         //then it means it doesn't want to use split-pipe but wants us to
         //decimate. A minimum decimation of 2 will ensure that the width is