-Wself-assign in drivers/scsi/nsp32.c

```
drivers/scsi/nsp32.c:2444:14: warning: explicitly assigning value of variable of type 'unsigned char' to itself [-Wself-assign]                
        offset      = offset;                                              
        ~~~~~~      ^
```

Patch submitted: https://lore.kernel.org/lkml/20181210235156.6237-1-natechancellor@gmail.com/