initialize nulLen to 0 for all compilers as some versions of gcc don't see that it's not used if left uninitialized too (bug 1469637)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@38696 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/strconv.cpp

@@ -179,7 +179,7 @@ wxMBConv::ToWChar(wchar_t *dst, size_t dstLen,
     size_t dstWritten = 0;
 
     // the number of NULs terminating this string
-    size_t nulLen wxDUMMY_INITIALIZE(0);
+    size_t nulLen = 0;  // not really needed, but just to avoid warnings
 
     // if we were not given the input size we just have to assume that the
     // string is properly terminated as we have no way of knowing how long it