[PATCH] t5318-commit-graph: remove unused variable

["SZEDER Gábor" <szeder.dev@gmail.com>]

This is a remnant from early versions of the commit-graph patch series
[1], when 'git commit-graph --write' printed the hash of the created
commit-graph file, and tests did look at the command's output, because
the commit-graph file's name included that hash as well.

[1] https://public-inbox.org/git/1517348383-112294-6-git-send-email-dstolee@microsoft.com/

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
---
 t/t5318-commit-graph.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index 561796f280..069e4e28e4 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -75,7 +75,7 @@ graph_read_expect() {
 
 test_expect_success 'write graph' '
 	cd "$TRASH_DIRECTORY/full" &&
-	graph1=$(git commit-graph write) &&
+	git commit-graph write &&
 	test_path_is_file $objdir/info/commit-graph &&
 	graph_read_expect "3"
 '
-- 
2.21.0.539.g07239c3a71.dirty