The mcg "too many pending requests" warning message fills the log
when OpenSM is downed. Demote the message from  warning level to
debug level.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>