drm/xe/guc: Extract function to print load error

drm/xe/guc: Extract function to print load error

Move the error parsing and print out of guc_wait_ucode() into a helper
to clean up the wait function. Since now the `load_done != 1` condition
has a return statement, also simplify the if/else chain.

Reviewed-by: John Harrison <John.C.Harrison@Intel.com> # v2
Link: https://lore.kernel.org/r/20250922-xe-iopoll-v4-4-06438311a63f@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>