drm/i915/guc: Actually return an error if GuC version range check fails

Dan Carpenter pointed out that 'err' was not being set in the case
where the GuC firmware version range check fails. Fix that.

Note that while this is a bug fix for a previous patch (see Fixes tag
below). It is an exceedingly low risk bug. The range check is
asserting that the GuC firmware version is within spec. So it should
not be possible to ever have a firmware file that fails this check. If
larger version numbers are required in the future, that would be a
backwards breaking spec change and thus require a major version bump,
in which case an old i915 driver would not load that new version anyway.

Fixes: 9bbba066 ("drm/i915/guc: Use GuC submission API version number")
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230421224742.2357198-1-John.C.Harrison@Intel.com