run-command: use void to declare that functions take no parameters

Explicitly declare that git_atexit_dispatch() and git_atexit_clear()
take no parameters instead of leaving their parameter list empty and
thus unspecified.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

run-command.c

@@ -636,7 +636,7 @@ static struct {
 
 static int git_atexit_installed;
 
-static void git_atexit_dispatch()
+static void git_atexit_dispatch(void)
 {
 	size_t i;
 
@@ -644,7 +644,7 @@ static void git_atexit_dispatch()
 		git_atexit_hdlrs.handlers[i-1]();
 }
 
-static void git_atexit_clear()
+static void git_atexit_clear(void)
 {
 	free(git_atexit_hdlrs.handlers);
 	memset(&git_atexit_hdlrs, 0, sizeof(git_atexit_hdlrs));