liboverlay: Do not dump error logs for pipe priority failures.

If validate call fails due to pipe priority mismatch, do not dump
overlay logs. For low tier targets, due to pipe crunching, these
failures are expected. Such frames will be handled by the next
composition strategy in the decision tree.

Change-Id: I00886f87239c8725ca1b03f9b5709bf3cc137566
diff --git a/liboverlay/overlayMdp.cpp b/liboverlay/overlayMdp.cpp
index 828f4fc..95bdc23 100644
--- a/liboverlay/overlayMdp.cpp
+++ b/liboverlay/overlayMdp.cpp
@@ -399,7 +399,7 @@
     int errVal = mdp_wrapper::validateAndSet(fbFd, list);
     if(errVal) {
         /* No dump for failure due to insufficient resource */
-        if(errVal != E2BIG) {
+        if(errVal != E2BIG && errVal != EBADSLT) {
             //ENODEV is returned when the driver cannot satisfy a pipe request.
             //This could happen if previous round's UNSET hasn't been commited
             //yet, either because of a missed vsync or because of difference in