driconf: Stop quoting true/false in boolean option definitions.

Now that we're not trying to evade preprocessor macro expansion in
preprocessor string concatenation, we can use plain old bools in option
setup.

Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6916>

src/util/xmlconfig.c

@@ -436,12 +436,7 @@ driParseOptionInfo(driOptionCache *info,
 
       switch (opt->info.type) {
       case DRI_BOOL:
-         if (strcmp(opt->value._string, "true") == 0)
-            optval->_bool = true;
-         else {
-            assert(strcmp(opt->value._string, "false") == 0);
-            optval->_bool = false;
-         }
+         optval->_bool = opt->value._bool;
          break;
 
       case DRI_INT: