t6300: make hash algorithm independent

One of the git for-each-ref tests asks to sort by object ID.  However,
when sorted, the order of the refs differs between SHA-1 and SHA-256.
Sort the expected output so that the test passes.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t6300-for-each-ref.sh

@@ -650,7 +650,7 @@ test_atom refs/tags/signed-long contents "subject line
 body contents
 $sig"
 
-cat >expected <<EOF
+sort >expected <<EOF
 $(git rev-parse refs/tags/bogo) <committer@example.com> refs/tags/bogo
 $(git rev-parse refs/tags/master) <committer@example.com> refs/tags/master
 EOF