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/libs/gui/Sensor.cpp b/libs/gui/Sensor.cpp
index 2545eec..1b40c87 100644
--- a/libs/gui/Sensor.cpp
+++ b/libs/gui/Sensor.cpp
@@ -38,7 +38,8 @@
 Sensor::Sensor()
     : mHandle(0), mType(0),
       mMinValue(0), mMaxValue(0), mResolution(0),
-      mPower(0), mMinDelay(0), mFifoReservedEventCount(0), mFifoMaxEventCount(0),
+      mPower(0), mMinDelay(0), mVersion(0), mFifoReservedEventCount(0),
+      mFifoMaxEventCount(0), mRequiredAppOp(0),
       mMaxDelay(0), mFlags(0)
 {
 }