tools: use long format for gpg fingerprint

Git has been using my Long format fingerprint in the tagging messages,
this has been causing the release script to fail on my keys.

It would also be wise to be using the long format on keys based on some
attacks that hack been found in the wild around short keys.

PR-URL: #9258
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rod Vagg <rod@vagg.org>

tools/release.sh

@@ -50,7 +50,7 @@ elif [ $keycount -ne 1 ]; then
   done
 fi
 
-gpgfing=$(gpg --fingerprint $gpgkey | grep 'Key fingerprint =' | awk -F' = ' '{print $2}' | tr -d ' ')
+gpgfing=$(gpg --keyid-format 0xLONG --fingerprint $gpgkey | grep 'Key fingerprint =' | awk -F' = ' '{print $2}' | tr -d ' ')
 
 if ! test "$(grep $gpgfing README.md)"; then
   echo 'Error: this GPG key fingerprint is not listed in ./README.md'