pcntl: remove unneeded module shutdown function (#16977)

Doesn't do anything, just returns `SUCCESS`

Author: DanielEScherzer

ext/pcntl/pcntl.c

@@ -153,7 +153,7 @@ zend_module_entry pcntl_module_entry = {
 	"pcntl",
 	ext_functions,
 	PHP_MINIT(pcntl),
-	PHP_MSHUTDOWN(pcntl),
+	NULL,
 	PHP_RINIT(pcntl),
 	PHP_RSHUTDOWN(pcntl),
 	PHP_MINFO(pcntl),
@@ -220,11 +220,6 @@ PHP_MINIT_FUNCTION(pcntl)
 	return SUCCESS;
 }
 
-PHP_MSHUTDOWN_FUNCTION(pcntl)
-{
-	return SUCCESS;
-}
-
 PHP_RSHUTDOWN_FUNCTION(pcntl)
 {
 	struct php_pcntl_pending_signal *sig;