drm/xe: Fix memory leak on xe_alloc_pf_queue failure

drm/xe: Fix memory leak on xe_alloc_pf_queue failure

Simplify memory unwinding on error also fixing current memory
leak that can happen on error.

v2: use devm_kcalloc(Matt A)

Fixes: 3338e4f90c14 ("drm/xe: Use topology to determine page fault queue size")
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Stuart Summers <stuart.summers@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240826162035.20462-1-nirmoy.das@intel.com
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>