be2net: disable bh with spin_lock in be_process_mcc

be_process_mcc() is invoked in 3 different places and
always with BHs disabled except the be_poll function
but since it's invoked from softirq with BHs
disabled it won't hurt.

v1->v2: added explanation to the patch
v2->v3: add a missing call from be_cmds.c

Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>