Fix return values for several syscall functions, patch by Zack Middleton (#5018)

code/server/sv_game.c

@@ -534,7 +534,7 @@ intptr_t SV_GameSystemCalls( intptr_t *args ) {
 
 	case BOTLIB_EA_ACTION:
 		botlib_export->ea.EA_Action( args[1], args[2] );
-		break;
+		return 0;
 	case BOTLIB_EA_GESTURE:
 		botlib_export->ea.EA_Gesture( args[1] );
 		return 0;
@@ -840,7 +840,7 @@ intptr_t SV_GameSystemCalls( intptr_t *args ) {
 	default:
 		Com_Error( ERR_DROP, "Bad game system trap: %ld", (long int) args[0] );
 	}
-	return -1;
+	return 0;
 }
 
 /*