libgui/SF: Fix some code warnings

A couple of fixes to satisfy the Eclipse static code analysis tool.
- Initialize all members in constructors
- Remove unused forward declarations
- Add parentheses when combining logical and bitwise operators
- Fix a case statement with no break (it was intentional)

Change-Id: Icecb8cc98c6f58b97ab33fffb621f0edc33a7d3c
diff --git a/services/surfaceflinger/MessageQueue.cpp b/services/surfaceflinger/MessageQueue.cpp
index 1ad86a6..99efd39 100644
--- a/services/surfaceflinger/MessageQueue.cpp
+++ b/services/surfaceflinger/MessageQueue.cpp
@@ -119,6 +119,7 @@
                 continue;
             case Looper::POLL_ERROR:
                 ALOGE("Looper::POLL_ERROR");
+                continue;
             case Looper::POLL_TIMEOUT:
                 // timeout (should not happen)
                 continue;