mm/slqb: replace deprecated function

cancel_rearming_delayed_work has been deprecated, the new equivalent
cancel_delayed_work_sync is used instead
RCU: Joe's RCU

Forward port jRCU to linux-3.0.

Thanks goes to Francisco Franco for his help
in testing out this version on the Android
Galaxy Nexus phone.

Signed-off-by: Joe Korty <joe.korty@ccur.com>