Fixes mismatching delete operator

Change-Id: Ib6640daa0fdd12f98f9d7e257c226e0abdcf31dc
Reviewed-by: Kevin Krammer <kevin.krammer@kdab.com>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>

src/corelib/codecs/qtextcodec.cpp

@@ -351,7 +351,7 @@ QString QWindowsLocalCodec::convertToUnicodeCharByChar(const char *chars, int le
         s.append(QChar(ws[i]));
     delete [] ws;
 #endif
-    delete mbcs;
+    delete [] mbcs;
     return s;
 }