ptp: ptp_clockmatrix: Clean-up dev_*() messages.

Code clean-up.

* Remove unnecessary \n termination from dev_*() messages.
* Remove 'char *fmt' to define strings to stay within 80 column
  limit.  Not needed since coding guidelines increased to
  100 columns limit.
  Keeping format in place allows static code checkers to
  validate the arguments.
* Tighten up vertical spacing.

Signed-off-by: Vincent Cheng <vincent.cheng.xh@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>