q2dm: correctly expect the return type of strchr(const char*) to be

'const char*' in C++ so that the code builds on gcc-4.4

ISO C++ overloads strchr() so that strchr(const char*) return 'const
char*' and strchr(char *) return 'char *'.
Since DmTrace::parseAndAddFunction really wants to write to its 'const
char *name' argument I just casted a pointer pointing inside of 'name' to 'char*'