Macros: Initialize some members in constructor

Detected by CppCheck

Change-Id: If47fcf7e256863eeabbfb9eace411d32238224c6
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/macros/macrosplugin.cpp

@@ -52,7 +52,7 @@
 
 using namespace Macros::Internal;
 
-MacrosPlugin::MacrosPlugin()
+MacrosPlugin::MacrosPlugin() : m_macroManager(0)
 {
 }