skd: Switch from the pr_*() to the dev_*() logging functions

Use dev_err() and dev_info() instead of pr_err() and pr_info().
Since dev_dbg() is able to report file name and line number
information, remove __FILE__ and __LINE__ from the dev_dbg() calls.
Remove the struct skd_device members and the function (skd_name())
that became superfluous due to these changes.

This patch removes the device name and serial number from log
statements. An example of the old log line format:

(skd0:STM000196603:[0000:00:09.0]): Driver state STARTING(3)=>ONLINE(4)

An example of the new log line format:

skd:0000:00:09.0: Driver state STARTING(3)=>ONLINE(4)
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>