media: st-delta: Fix reference count leak in delta_run_work

delta_run_work() calls delta_get_sync() that increments
the reference counter. In case of failure, decrement the reference
count by calling delta_put_autosuspend().

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>