scsi: qedf: Add more defensive checks for concurrent error conditions

During an uplink toggle test all error handling is done via timeout and
firmware error conditions which can occur concurrently:

 - SCSI layer timeouts
 - Error detect CQEs
 - Firmware detected underruns
 - ABTS timeouts

All these concurrent events require more defensive checks in the driver
including:

 - Check both internally and externally generated aborts to make sure the
   xid is not already been aborted in another context or in cleanup.

 - Check back pointers in qedf_cmd_timeout to verify the context of the
   io_req, fcport and qedf_ctx

 - Check rport state in host reset handler to not reset the whole host
   if the rport is already uploaded or in the process of relogin

 - Check to state for an fcport before initiating a middle path ELS
   request

Signed-off-by: Chad Dupuis <chad.dupuis@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>