Return the unit number of a channel instead of a hardcoded '1' from the ATA pccard locking function.  This makes pccard devices like Compact Flash cards work again.
Return the unit number of a channel instead of a hardcoded '1' from
the ATA pccard locking function.  This makes pccard devices like
Compact Flash cards work again.

PR:             kern/72805
Submitted by:   James E. Flemer <jflemer@alum.rpi.edu>
MFC in:         2 days

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