perf hist: Improve srcfile sort key performance (really)

The earlier commit f0cdde28 ("perf hist: Improve srcfile sort
key performance") updated the srcfile logic but missed to change the
->cmp() callback which is called for every sample.

It should use the same logic like in the srcline to speed up the
processing because it'd return the same information repeatedly for the
same address.  The real processing will be done in
sort__srcfile_collapse().

Fixes: f0cdde28 ("perf hist: Improve srcfile sort key performance")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230323025005.191239-1-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/sort.c

@@ -657,12 +657,7 @@ static char *hist_entry__get_srcfile(struct hist_entry *e)
 static int64_t
 sort__srcfile_cmp(struct hist_entry *left, struct hist_entry *right)
 {
-	if (!left->srcfile)
-		left->srcfile = hist_entry__get_srcfile(left);
-	if (!right->srcfile)
-		right->srcfile = hist_entry__get_srcfile(right);
-
-	return strcmp(right->srcfile, left->srcfile);
+	return sort__srcline_cmp(left, right);
 }
 
 static int64_t