perf machine: Use true and false for bool variable

Fix the following coccicheck warnings:

./tools/perf/util/machine.c:2000:9-10: WARNING: return of 0/1 in
function 'symbol__match_regex' with return type bool.

Committer notes:

Found this in the pile, it was already returning bool, but this patch
simplifies it further, from 3 lines to just 1.

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Jiapeng Chong <[email protected]>
Suggested-by: David Laight <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Fastabend <[email protected]>
Cc: KP Singh <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Yonghong Song <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/1614247483-102665-1-git-send-email-jiapeng.chong@linux.alibaba.com
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: Jiapeng Chong

tools/perf/util/machine.c

@@ -2213,9 +2213,7 @@ int machine__process_event(struct machine *machine, union perf_event *event,
 
 static bool symbol__match_regex(struct symbol *sym, regex_t *regex)
 {
-	if (!regexec(regex, sym->name, 0, NULL, 0))
-		return true;
-	return false;
+	return regexec(regex, sym->name, 0, NULL, 0) == 0;
 }
 
 static void ip__resolve_ams(struct thread *thread,