perf tools: Move all users of event_name to perf_evsel__name

So that we don't use global variables that could make us misreport event
names when having a multi window top, for instance.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-mccancovi1u0wdkg8ncth509@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-record.c

@@ -265,7 +265,7 @@ try_again:
 
 			if (err == ENOENT) {
 				ui__error("The %s event is not supported.\n",
-					    event_name(pos));
+					  perf_evsel__name(pos));
 				exit(EXIT_FAILURE);
 			}
 
@@ -916,7 +916,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
 		usage_with_options(record_usage, record_options);
 
 	list_for_each_entry(pos, &evsel_list->entries, node) {
-		if (perf_header__push_event(pos->attr.config, event_name(pos)))
+		if (perf_header__push_event(pos->attr.config, perf_evsel__name(pos)))
 			goto out_free_fd;
 	}