Revert "pmem: Make request/release region return a value"

This reverts commit c17fea511e11807c02cdb4dedee00fe26d5b9637.
CPU: Allow CPU-based alignment handling
irq: Set CPU affinity as soon as the irq thread is created

In an embedded target where IRQ affinities are pre-configured during
boot-time (and not modified through /proc/irq/../smp_affinity) during
run-time, the extra latency due to irq_thread_check_affinity can be
avoided during processing of the first interrupt with this patch.
Thoughts?

backported from Linux 3.5+ by faux123