scsi: qla4xxx: Remove redundant assignment to variable rval

The variable rval has been initialized with 'QLA_ERROR'. The assignment is
redundant in an error path. Remove it.

Link: https://lore.kernel.org/r/20201103120137.109717-1-jingxiangfeng@huawei.com


Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>