t/t5403-post-checkout-hook.sh: avoid "test <cond> -a/-o <cond>"

The construct is error-prone; "test" being built-in in most modern
shells, the reason to avoid "test <cond> && test <cond>" spawning
one extra process by using a single "test <cond> -a <cond>" no
longer exists.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5403-post-checkout-hook.sh

@@ -39,7 +39,7 @@ test_expect_success 'post-checkout receives the right arguments with HEAD unchan
 	old=$(awk "{print \$1}" clone1/.git/post-checkout.args) &&
 	new=$(awk "{print \$2}" clone1/.git/post-checkout.args) &&
 	flag=$(awk "{print \$3}" clone1/.git/post-checkout.args) &&
-	test $old = $new -a $flag = 1
+	test $old = $new && test $flag = 1
 '
 
 test_expect_success 'post-checkout runs as expected ' '
@@ -52,23 +52,23 @@ test_expect_success 'post-checkout args are correct with git checkout -b ' '
 	old=$(awk "{print \$1}" clone1/.git/post-checkout.args) &&
 	new=$(awk "{print \$2}" clone1/.git/post-checkout.args) &&
 	flag=$(awk "{print \$3}" clone1/.git/post-checkout.args) &&
-	test $old = $new -a $flag = 1
+	test $old = $new && test $flag = 1
 '
 
 test_expect_success 'post-checkout receives the right args with HEAD changed ' '
 	GIT_DIR=clone2/.git git checkout new2 &&
 	old=$(awk "{print \$1}" clone2/.git/post-checkout.args) &&
 	new=$(awk "{print \$2}" clone2/.git/post-checkout.args) &&
 	flag=$(awk "{print \$3}" clone2/.git/post-checkout.args) &&
-	test $old != $new -a $flag = 1
+	test $old != $new && test $flag = 1
 '
 
 test_expect_success 'post-checkout receives the right args when not switching branches ' '
 	GIT_DIR=clone2/.git git checkout master b &&
 	old=$(awk "{print \$1}" clone2/.git/post-checkout.args) &&
 	new=$(awk "{print \$2}" clone2/.git/post-checkout.args) &&
 	flag=$(awk "{print \$3}" clone2/.git/post-checkout.args) &&
-	test $old = $new -a $flag = 0
+	test $old = $new && test $flag = 0
 '
 
 if test "$(git config --bool core.filemode)" = true; then