HSI: ssi_protocol: fix struct members kernel-doc warnings

Fix a typo in one struct member's name and add the @work struct member
to quieten kernel-doc warnings:

ssi_protocol.c:144: warning: Function parameter or struct member 'work' not described in 'ssi_protocol'
ssi_protocol.c:144: warning: Function parameter or struct member 'tx_usecnt' not described in 'ssi_protocol'
ssi_protocol.c:144: warning: Excess struct member 'tx_usecount' description in 'ssi_protocol'

Signed-off-by: Randy Dunlap <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/hsi/clients/ssi_protocol.c

···
  * @netdev: Phonet network device
  * @txqueue: TX data queue
  * @cmdqueue: Queue of free commands
+ * @work: &struct work_struct for scheduled work
  * @cl: HSI client own reference
  * @link: Link for ssip_list
- * @tx_usecount: Refcount to keep track the slaves that use the wake line
+ * @tx_usecnt: Refcount to keep track the slaves that use the wake line
  * @channel_id_cmd: HSI channel id for command stream
  * @channel_id_data: HSI channel id for data stream
  */