git submodule foreach: test access to submodule name as '$name'

Add verification of the behaviour of '$name' to the git submodule
foreach selftest.

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7407-submodule-foreach.sh

@@ -61,17 +61,17 @@ sub3sha1=$(cd super/sub3 && git rev-parse HEAD)
 
 cat > expect <<EOF
 Entering 'sub1'
-sub1-$sub1sha1
+foo1-sub1-$sub1sha1
 Entering 'sub3'
-sub3-$sub3sha1
+foo3-sub3-$sub3sha1
 EOF
 
 test_expect_success 'test basic "submodule foreach" usage' '
 	git clone super clone &&
 	(
 		cd clone &&
 		git submodule update --init -- sub1 sub3 &&
-		git submodule foreach "echo \$path-\$sha1" > ../actual
+		git submodule foreach "echo \$name-\$path-\$sha1" > ../actual
 	) &&
 	test_cmp expect actual
 '