Use previously unused variable in fixture script (#383)

Author: Byron

git-repository/tests/fixtures/generated-archives/make_am_repo.tar.xz

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:357c85ba0f2c4e8703e643ebbebc49229d0560eb0e6ed1ffa08969d4750f5bc5
-size 11356
+oid sha256:87c31f0b601dae0e2b7d863be659b80507b21527d6788a50253181c4f3d5f054
+size 11360

git-repository/tests/fixtures/make_am_repo.sh

@@ -19,4 +19,4 @@ echo file.main.update > file
 git commit -m file.main.update file
 
 # This will fail due to the merge conflict and leave us in a 'apply mbox in progress' state
-git am 0001-file.other-branch.patch || true
+git am "$patch_path" || true