t/lib-commit-graph.sh: avoid sub-shell in graph_git_behavior()

In a previous commit, we introduced a sub-shell in the implementation of
`graph_git_behavior()`, in order to allow us to pass `-C "$DIR"`
directly to the git processes spawned by `graph_git_two_modes()`.

Now that its callers are always operating from the "$TRASH_DIRECTORY"
instead of one of its sub-directories, we can drop the inner sub-shell,
as it is no longer required.

Signed-off-by: Taylor Blau <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: ttaylorr

t/lib-commit-graph.sh

@@ -27,14 +27,11 @@ graph_git_behavior() {
 	BRANCH=$3
 	COMPARE=$4
 	test_expect_success "check normal git operations: $MSG" '
-		(
-			cd "$TRASH_DIRECTORY" &&
-			graph_git_two_modes "${DIR:+-C $DIR} log --oneline $BRANCH" &&
-			graph_git_two_modes "${DIR:+-C $DIR} log --topo-order $BRANCH" &&
-			graph_git_two_modes "${DIR:+-C $DIR} log --graph $COMPARE..$BRANCH" &&
-			graph_git_two_modes "${DIR:+-C $DIR} branch -vv" &&
-			graph_git_two_modes "${DIR:+-C $DIR} merge-base -a $BRANCH $COMPARE"
-		)
+		graph_git_two_modes "${DIR:+-C $DIR} log --oneline $BRANCH" &&
+		graph_git_two_modes "${DIR:+-C $DIR} log --topo-order $BRANCH" &&
+		graph_git_two_modes "${DIR:+-C $DIR} log --graph $COMPARE..$BRANCH" &&
+		graph_git_two_modes "${DIR:+-C $DIR} branch -vv" &&
+		graph_git_two_modes "${DIR:+-C $DIR} merge-base -a $BRANCH $COMPARE"
 	'
 }