[media] marvell-ccic: refine mcam_set_contig_buffer function

This patch refines mcam_set_contig_buffer() in mcam core.
It can remove redundant code line and enhance readability.

Signed-off-by: Albert Wang <twang13@marvell.com>
Signed-off-by: Libin Yang <lbyang@marvell.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>