perf thread: Make thread__find_map() return the map

It was returning the searched map just on the addr_location passed, with
the function itself returning void.

Make it return the map so that we can make the code more compact.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-tzlrrzdeoof4i6ktyqv1t6ks@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/unwind-libunwind-local.c

@@ -367,8 +367,7 @@ static struct map *find_map(unw_word_t ip, struct unwind_info *ui)
 {
 	struct addr_location al;
 
-	thread__find_map(ui->thread, PERF_RECORD_MISC_USER, ip, &al);
-	if (!al.map) {
+	if (!thread__find_map(ui->thread, PERF_RECORD_MISC_USER, ip, &al)) {
 		/*
 		 * We've seen cases (softice) where DWARF unwinder went
 		 * through non executable mmaps, which we need to lookup