media: staging: atomisp: hmm: Fixed comment style

This patch fixed comment style. Semantic should not be affected.
There are also two warnings left about too long lines, which
reduce readability if changed.

Signed-off-by: Philipp Guendisch <philipp.guendisch@fau.de>
Signed-off-by: Chris Baller <chris.baller@gmx.de>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>