Finish fixing memleak in ssl_server2 arg parsing

Fixes omission in 5c078e1
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index d1b76ac..30814eb 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -587,7 +587,7 @@
     while( p <= end )
     {
         if( ( new = polarssl_malloc( sizeof( psk_entry ) ) ) == NULL )
-            return( NULL );
+            goto error;
 
         memset( new, 0, sizeof( psk_entry ) );