cris-tdep.c: Use unsigned variable for unsigned command.

cris-tdep.c: Use unsigned variable for unsigned command.

"set cris-version" is an unsigned command:

    /* CRIS-specific user-commands.  */
    add_setshow_uinteger_cmd ("cris-version", class_support,
  			    &usr_cmd_cris_version,
  			    _("Set the current CRIS version."),
  			    _("Show the current CRIS version."),
  			    _("\
  Set to 10 for CRISv10 or 32 for CRISv32 if autodetection fails.\n\
  Defaults to 10. "),

Tested by building on x86_64 Fedora 17.

2013-04-19  Pedro Alves  <palves@redhat.com>

	* cris-tdep.c (usr_cmd_cris_version): Make unsigned.
	(struct gdbarch_tdep) <cris_version>: Make unsigned.
	(cris_spec_reg_applicable, cris_gdbarch_init): Adjust locals.