If an interrupt event's assign_cpu method fails, then restore the original cpuset mask for the associated interrupt thread.
If an interrupt event's assign_cpu method fails, then restore the original
cpuset mask for the associated interrupt thread.

The text used above is verbatim from r195249 and the code should now be
in line with the intent of that commit.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase