[SCSI] zfcp: Simplify ccw notify handler

The notify handler does not change the list of adapters, it only
triggers erp actions to open or shutdown the adapter. We don't
need to hold the config semaphore and wait for the erp to complete.

This is a prerequisite for a fix in the s390 common i/o code.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>