patch 8.1.1393: unnecessary type casts

Problem:    Unnecessary type casts.
Solution:   Remove type casts from alloc() and lalloc() calls. (Mike Williams)

src/regexp_nfa.c

@@ -4799,7 +4799,7 @@ addstate_here(
 		emsg(_(e_maxmempat));
 		return NULL;
 	    }
-	    newl = (nfa_thread_T *)alloc((int)newsize);
+	    newl = (nfa_thread_T *)alloc(newsize);
 	    if (newl == NULL)
 		return NULL;
 	    l->len = newlen;