drm/i915: Fixup kerneldoc in struct i915_gem_context

Mixup in rebasing and patchwork re-runs made me push the wrong version of
the patch. Or I even forgot to send out the fixed version. Fix it up.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 49bd54b3

 ("drm/i915: Track all user contexts per client")
Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405155345.3292769-1-tvrtko.ursulin@linux.intel.com