scsi: qla2xxx: Correct error handling during initialization failures

Current code misses or fails to account for proper recovery during early
initialization failures:

 - Properly unwind allocations during probe() failures.

 - Protect against non-initialization memory allocations during
   unwinding.

 - Propagate error status during HW initialization.

 - Release SCSI host reference when memory allocations fail.

Signed-off-by: Andrew Vasquez <andrewv@marvell.com>
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>