perf debug: Avoid stack overflow in recursive error message

[ Upstream commit bda840191d2aae3b7cadc3ac21835dcf29487191 ]

In debug_file, pr_warning_once is called on error. As that function
calls debug_file the function will yield a stack overflow. Switch the
location of the call so the recursion is avoided.

Reviewed-by: Howard Chu <howardchu95@gmail.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20250228222308.626803-2-irogers@google.com
Fixes: ec49230cf6 ("perf debug: Expose debug file")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

tools/perf/util/debug.c

@@ -46,8 +46,8 @@ int debug_type_profile;
 FILE *debug_file(void)
 {
 	if (!_debug_file) {
-		pr_warning_once("debug_file not set");
 		debug_set_file(stderr);
+		pr_warning_once("debug_file not set");
 	}
 	return _debug_file;
 }