daemon: be strict at parsing parameters --[no-]informative-errors

Use strcmp() instead of starts_with()/!prefixcmp() to stop accepting
--informative-errors-just-a-little

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

daemon.c

@@ -1278,11 +1278,11 @@ int main(int argc, char **argv)
 			make_service_overridable(arg + 18, 0);
 			continue;
 		}
-		if (!prefixcmp(arg, "--informative-errors")) {
+		if (!strcmp(arg, "--informative-errors")) {
 			informative_errors = 1;
 			continue;
 		}
-		if (!prefixcmp(arg, "--no-informative-errors")) {
+		if (!strcmp(arg, "--no-informative-errors")) {
 			informative_errors = 0;
 			continue;
 		}