t8003: make hash size independent

One assertion in this test invokes git with core.abbrev set to "40".
Since we're expecting the full hash length, use test_oid to look up the
full hash length for the hash in use.

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

t/t8003-blame-corner-cases.sh

@@ -6,7 +6,6 @@ test_description='git blame corner cases'
 pick_fc='s/^[0-9a-f^]* *\([^ ]*\) *(\([^ ]*\) .*/\1-\2/'
 
 test_expect_success setup '
-
 	echo A A A A A >one &&
 	echo B B B B B >two &&
 	echo C C C C C >tres &&
@@ -306,7 +305,7 @@ test_expect_success 'blame coalesce' '
 	$oid 1) ABC
 	$oid 2) DEF
 	EOF
-	git -c core.abbrev=40 blame -s giraffe >actual &&
+	git -c core.abbrev=$(test_oid hexsz) blame -s giraffe >actual &&
 	test_cmp expect actual
 '