t1507: abstract away SHA-1-specific constants

Adjust the test so that it uses a variable consisting of the current
HEAD instead of a hard-coded hash.

Signed-off-by: brian m. carlson <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: bk2204

t/t1507-rev-parse-upstream.sh

@@ -209,8 +209,9 @@ test_expect_success '@{u} works when tracking a local branch' '
 	test refs/heads/master = "$(full_name @{u})"
 '
 
+commit=$(git rev-parse HEAD)
 cat >expect <<EOF
-commit 8f489d01d0cc65c3b0f09504ec50b5ed02a70bd5
+commit $commit
 Reflog: master@{0} (C O Mitter <[email protected]>)
 Reflog message: branch: Created from HEAD
 Author: A U Thor <[email protected]>
@@ -224,7 +225,7 @@ test_expect_success 'log -g other@{u}' '
 '
 
 cat >expect <<EOF
-commit 8f489d01d0cc65c3b0f09504ec50b5ed02a70bd5
+commit $commit
 Reflog: master@{Thu Apr 7 15:17:13 2005 -0700} (C O Mitter <[email protected]>)
 Reflog message: branch: Created from HEAD
 Author: A U Thor <[email protected]>