drm/i915/display: Use correct method to free crtc_state

Even though there is no leaking of resource here lets
just use the correct method to free crtc_state

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231010183101.704439-3-suraj.kandpal@intel.com