Changed multi-line C comments into another style.

The left side doesn't look unbalanced.

src/ca65/easw16.c

@@ -51,9 +51,9 @@
 
 static long RegNum ()
 /* Try to read a register number specified not as a register (Rx) but as a
- * numeric value between 0 and 15. Return the register number or -1 on
- * failure.
- */
+** numeric value between 0 and 15. Return the register number or -1 on
+** failure.
+*/
 {
     long Val;
     ExprNode* Expr = Expression ();
@@ -126,8 +126,8 @@ void GetSweet16EA (EffAddr* A)
         A->AddrModeSet = AMSW16_BRA;
 
         /* If the value is a constant between 0 and 15, it may also be a
-         * register number.
-         */
+        ** register number.
+        */
         if (IsConstExpr (A->Expr, &Reg) && Reg >= 0 && Reg <= 15) {
             FreeExpr (A->Expr);
             A->Reg = (unsigned) Reg;