Changed multi-line C comments into another style.

The left side doesn't look unbalanced.

src/sim65/memory.h

@@ -55,9 +55,9 @@ unsigned MemReadWord (unsigned Addr);
 
 unsigned MemReadZPWord (unsigned char Addr);
 /* Read a word from the zero page. This function differs from ReadMemW in that
- * the read will always be in the zero page, even in case of an address
- * overflow.
- */
+** the read will always be in the zero page, even in case of an address
+** overflow.
+*/
 
 void MemInit (void);
 /* Initialize the memory subsystem */