t5703: use test_commit_bulk

There are two loops that create 33 commits each using test_commit. Using
test_commit_bulk speeds this up from:

  Benchmark #1: ./t5703-upload-pack-ref-in-want.sh --root=/var/ram/git-tests
    Time (mean ± σ):      2.142 s ±  0.161 s    [User: 1.136 s, System: 0.974 s]
    Range (min … max):    1.903 s …  2.401 s    10 runs

to:

  Benchmark #1: ./t5703-upload-pack-ref-in-want.sh --root=/var/ram/git-tests
    Time (mean ± σ):      1.440 s ±  0.114 s    [User: 737.7 ms, System: 615.4 ms]
    Range (min … max):    1.230 s …  1.604 s    10 runs

for an average savings of almost 33%.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5703-upload-pack-ref-in-want.sh

@@ -176,7 +176,7 @@ test_expect_success 'setup repos for change-while-negotiating test' '
 		git clone "http://127.0.0.1:$LIB_HTTPD_PORT/smart/repo" "$LOCAL_PRISTINE" &&
 		cd "$LOCAL_PRISTINE" &&
 		git checkout -b side &&
-		for i in $(test_seq 1 33); do test_commit s$i; done &&
+		test_commit_bulk --id=s 33 &&
 
 		# Add novel commits to upstream
 		git checkout master &&
@@ -287,7 +287,7 @@ test_expect_success 'setup repos for fetching with ref-in-want tests' '
 		git clone "file://$REPO" "$LOCAL_PRISTINE" &&
 		cd "$LOCAL_PRISTINE" &&
 		git checkout -b side &&
-		for i in $(test_seq 1 33); do test_commit s$i; done &&
+		test_commit_bulk --id=s 33 &&
 
 		# Add novel commits to upstream
 		git checkout master &&