[PATCH] S12Z: Don't crash when disassembling invalid instructions.

[Nick Clifton]

Hi John,

> 	* opcodes/s12z-dis.c (print_insn_s12z):  Do not derefernce an
> 	operand if it is null.

Approved, please apply.  But please note that the changelog entry
should go in the opcodes/ChangeLog file, and hence there is no need
for "opcodes/" to appear in the path in the changelog entry.

Cheers
  Nick