staging: most: dim2: remove unnecessary NULL check in service_done_flag()

staging: most: dim2: remove unnecessary NULL check in service_done_flag()

Remove the !hdm_ch check. hdm_ch is derived from dev->hch + ch_idx
(pointer arithmetic on a struct member), so it can never be NULL.
Keep only the !hdm_ch->is_initialized check.

Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/all/acuoL4DRi0pmsQY1@stanley.mountain
Signed-off-by: Gabriel Rondon <grondon@gmail.com>
Link: https://patch.msgid.link/20260331164443.47682-1-grondon@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>