Fix absolute-indexed addressing mode instruction decoding

opcodes.c

@@ -22,9 +22,9 @@ static int adr_abs(const uint8_t* operand, char* str, int max) {
     return snprintf(str, max, "$%04X", *(uint16_t*)operand);
 }
 
-static inline int adr_abs_reg(char reg, const uint8_t* operand,
+static inline int adr_abs_reg(char reg, const uint8_t* op,
                               char* str, int max) {
-    return snprintf(str, max, "$%04X,%c", *operand, reg);
+    return snprintf(str, max, "$%04X,%c", *(uint16_t*)op, reg);
 }
 
 static int adr_abs_x(const uint8_t* operand, char* str, int max) {