Rename MonsterTrapHit m parameter to monsterId

Source/missiles.cpp

@@ -840,9 +840,9 @@ Direction16 GetDirection16(Point p1, Point p2)
 	return ret;
 }
 
-bool MonsterTrapHit(int m, int mindam, int maxdam, int dist, missile_id t, bool shift)
+bool MonsterTrapHit(int monsterId, int mindam, int maxdam, int dist, missile_id t, bool shift)
 {
-	auto &monster = Monsters[m];
+	auto &monster = Monsters[monsterId];
 
 	if (!monster.IsPossibleToHit() || monster.IsImmune(t))
 		return false;
@@ -877,7 +877,7 @@ bool MonsterTrapHit(int m, int mindam, int maxdam, int dist, missile_id t, bool
 		PlayEffect(monster, 1);
 	} else {
 		if (monster.type().type != MT_GOLEM)
-			M_StartHit(m, dam);
+			M_StartHit(monsterId, dam);
 	}
 	return true;
 }

Source/missiles.h

@@ -160,7 +160,7 @@ void GetDamageAmt(spell_id i, int *mind, int *maxd);
  * @return the direction of the p1->p2 vector
  */
 Direction16 GetDirection16(Point p1, Point p2);
-bool MonsterTrapHit(int m, int mindam, int maxdam, int dist, missile_id t, bool shift);
+bool MonsterTrapHit(int monsterId, int mindam, int maxdam, int dist, missile_id t, bool shift);
 bool PlayerMHit(int pnum, Monster *monster, int dist, int mind, int maxd, missile_id mtype, bool shift, int earflag, bool *blocked);
 
 /**