t7401: modernize style

The tests in 't7401-submodule-summary.sh' were written a long time ago
and has a violation with respect to our CodingGuidelines which is,
incorrect spacing in usages of the redirection operator.

Mentored-by: Christian Couder <[email protected]>
Mentored-by: Kaartic Sivaraam <[email protected]>
Helped-by: Denton Liu <[email protected]>
Helped-by: Taylor Blau <[email protected]>
Signed-off-by: Shourya Shukla <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: periperidip

t/t7401-submodule-summary.sh

@@ -16,7 +16,7 @@ add_file () {
 	owd=$(pwd)
 	cd "$sm"
 	for name; do
-		echo "$name" > "$name" &&
+		echo "$name" >"$name" &&
 		git add "$name" &&
 		test_tick &&
 		git commit -m "Add $name"