fix: util/check-format-commit.sh - fix ending check

Look at the end result instead of the file name it's stored in

Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/25810)

util/check-format-commit.sh

@@ -164,7 +164,7 @@ done
 cat $TEMPDIR/results-filtered.txt
 
 # If any findings were in range, exit with a different error code
-if [ -n $TEMPDIR/results-filtered.txt ]
+if [ -s $TEMPDIR/results-filtered.txt ]
 then
     exit 2
 fi