Fix compilation warnings

Various small issues:
* Member initialization order
* Comparison of different signedness
* Unused parameters
* Unused variable

Change-Id: Ie59db239b4216ad089f7cf0f289e6ed3d6ac8e18
Signed-off-by: Jonathan Doman <jonathan.doman@intel.com>
diff --git a/src/cpu.cpp b/src/cpu.cpp
index ed4eabb..d9fd212 100644
--- a/src/cpu.cpp
+++ b/src/cpu.cpp
@@ -108,7 +108,7 @@
     {
         if (charBits.test(index))
         {
-            if (cap = characteristicsTable[index])
+            if ((cap = characteristicsTable[index]))
             {
                 result.emplace_back(*cap);
             }