b=12211
origianl patch producer=adilger
i=green, bobijam

move obd_fail_check() from being a static inline to being a function.
We already protect this function from being called needlessly by use of
unlikely() and checking obd_fail_loc != 0 before calling it.

Having such a large function inline bloats the code and likely reduces
performance by putting extra (though unlikely) code in every function.