coccicheck: change handling of C={1,2} when M= is set

This patch reverts a portion of d0bc1fb4

 so that coccicheck will
work properly when C=1 or C=2.

Reported-and-tested-by: Brice Goglin <Brice.Goglin@inria.fr>
Signed-off-by: Greg Dietsche <Gregory.Dietsche@cuw.edu>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>