t1407: make hash size independent

Instead of hard-coding a 40-based constant, split the output of
for-each-ref and for-each-reflog by field.

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

t/t1407-worktree-ref-store.sh

@@ -58,7 +58,7 @@ test_expect_success 'for_each_reflog()' '
 	mkdir -p     .git/worktrees/wt/logs/refs/bisect &&
 	echo $ZERO_OID > .git/worktrees/wt/logs/refs/bisect/wt-random &&
 
-	$RWT for-each-reflog | cut -c 42- | sort >actual &&
+	$RWT for-each-reflog | cut -d" " -f 2- | sort >actual &&
 	cat >expected <<-\EOF &&
 	HEAD 0x1
 	PSEUDO-WT 0x0
@@ -68,7 +68,7 @@ test_expect_success 'for_each_reflog()' '
 	EOF
 	test_cmp expected actual &&
 
-	$RMAIN for-each-reflog | cut -c 42- | sort >actual &&
+	$RMAIN for-each-reflog | cut -d" " -f 2- | sort >actual &&
 	cat >expected <<-\EOF &&
 	HEAD 0x1
 	PSEUDO-MAIN 0x0