Merge branch 'ag/p3400-force-checkout'

Perf test tweak.

* ag/p3400-force-checkout:
  p3400: replace calls to `git checkout -b' by `git checkout -B'

Author: gitster

t/perf/p3400-rebase.sh

@@ -6,9 +6,9 @@ test_description='Tests rebase performance'
 test_perf_default_repo
 
 test_expect_success 'setup rebasing on top of a lot of changes' '
-	git checkout -f -b base &&
-	git checkout -b to-rebase &&
-	git checkout -b upstream &&
+	git checkout -f -B base &&
+	git checkout -B to-rebase &&
+	git checkout -B upstream &&
 	for i in $(seq 100)
 	do
 		# simulate huge diffs
@@ -35,8 +35,8 @@ test_perf 'rebase on top of a lot of unrelated changes' '
 
 test_expect_success 'setup rebasing many changes without split-index' '
 	git config core.splitIndex false &&
-	git checkout -b upstream2 to-rebase &&
-	git checkout -b to-rebase2 upstream
+	git checkout -B upstream2 to-rebase &&
+	git checkout -B to-rebase2 upstream
 '
 
 test_perf 'rebase a lot of unrelated changes without split-index' '