drm/dp_mst: Remove rebase-detritus in VCPI helper kernel-docs

Looks like when making the final revision of:

commit 022debad ("drm/atomic: Add drm_atomic_state->duplicated")

I forgot to remove some of the comments that I had added to
drm_dp_atomic_find_vcpi_slots() and drm_dp_atomic_release_vcpi_slots()
that were no longer valid due to us having removed the state->duplicated
checks from each function. This also introduced an error while building
the docs with sphinx:

./drivers/gpu/drm/drm_dp_mst_topology.c:3100: WARNING: Inline literal
start-string without end-string.

So, fix that by just removing the kerneldoc comments.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: 022debad ("drm/atomic: Add drm_atomic_state->duplicated")
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190202002023.29665-5-lyude@redhat.com