drm/i915/hdcp: fix connector refcounting

drm/i915/hdcp: fix connector refcounting

We acquire a connector reference before scheduling an HDCP prop work,
and expect the work function to release the reference.

However, if the work was already queued, it won't be queued multiple
times, and the reference is not dropped.

Release the reference immediately if the work was already queued.

Fixes: a6597faa2d59 ("drm/i915: Protect workers against disappearing connectors")
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Suraj Kandpal <suraj.kandpal@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org # v5.10+
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240924153022.2255299-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>