t1400: remove a set of unused output files

This test case redirects stdout and stderr to output files, but,
unlike the other cases of redirection in the t1400 tests, these files
are not examined downstream.  Remove the redirection so that the
output is visible when running the tests verbosely.

Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t1400-update-ref.sh

@@ -64,8 +64,8 @@ rm -f .git/$m
 test_expect_success \
 	"fail to create $n" \
 	"touch .git/$n_dir &&
-	 test_must_fail git update-ref $n $A >out 2>err"
-rm -f .git/$n_dir out err
+	 test_must_fail git update-ref $n $A"
+rm -f .git/$n_dir
 
 test_expect_success \
 	"create $m (by HEAD)" \