perf tp_pmu: Address const-correctness errors in recent glibcs

To avoid having more variables, just cast the const variable searched to
non-const since the result will not be modified, its only later that
that variable will be used to modify something, but then its non-const
memory being modified, so using a cast is the cheapest thing here.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/tp_pmu.c

@@ -192,7 +192,7 @@ bool tp_pmu__have_event(struct perf_pmu *pmu __maybe_unused, const char *name)
 	char *dup_name, *colon;
 	int id;
 
-	colon = strchr(name, ':');
+	colon = strchr((char *)name, ':');
 	if (colon == NULL)
 		return false;