Use a more typical kernel logging style.

The current macro hides the gspca_dev argument so add it to the
macro uses instead.

Miscellanea:

o Add missing '\n' terminations to formats
o Realign arguments to open parenthesis
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>