r600g: Disable unused variables.

The variables are used only in currently disabled code.

Fixes this GCC warning.
r600_context.c: In function 'r600_flush':
r600_context.c:76: warning: unused variable 'dname'
r600_context.c:75: warning: unused variable 'dc'

src/gallium/drivers/r600/r600_context.c

@@ -71,7 +71,7 @@ void r600_flush(struct pipe_context *ctx, unsigned flags,
 {
 	struct r600_context *rctx = r600_context(ctx);
 	struct r600_query *rquery = NULL;
-#if 1
+#if 0
 	static int dc = 0;
 	char dname[256];
 #endif