(sd): Supply missing parenthesis for a cast from double to int. The

cast is only there to express intent, it doesn't change the meaning of
the code.

src/lib/subs/fortdef.c

@@ -144,7 +144,7 @@ sd(natid att, natid own, coord x, coord y, int noisy, int defending,
 	    }
 	}
     }
-    return (int)100 - eff * 100;
+    return (int)(100 - eff * 100);
 }
 
 int