Clean up memory

And remove a test failure when compiling with asan enabled.

Change-Id: I2b8e676665572adcbbac6a910983d5b209bf6d23
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

tests/auto/corelib/codecs/qtextcodec/echo/main.cpp

@@ -42,6 +42,7 @@ int main(int argc, char **argv)
     QTextEncoder *encoder = locale->makeEncoder();
     QByteArray output = encoder->fromUnicode(string);
     printf("%s\n", output.data());
+    delete encoder;
 
     return 0;
 }