adding wxFALLTHROUGH where until now we had comments, allows for code-analysis support

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76399 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/process.cpp

@@ -169,7 +169,7 @@ bool wxProcess::Exists(int pid)
         case wxKILL_ERROR:
         case wxKILL_BAD_SIGNAL:
             wxFAIL_MSG( wxT("unexpected wxProcess::Kill() return code") );
-            // fall through
+            wxFALLTHROUGH;
 
         case wxKILL_NO_PROCESS:
             return false;