scsi: fnic: make array dev_cmd_err static const, makes object smaller

Don't populate the array dev_cmd_err on the stack but instead make it
static const. Makes the object code smaller by 80 bytes.

Before:
   text	   data	    bss	    dec	    hex	filename
  21461	   1564	      0	  23025	   59f1	drivers/scsi/fnic/vnic_dev.o

After:
   text	   data	    bss	    dec	    hex	filename
  21318	   1628	      0	  22946	   59a2	drivers/scsi/fnic/vnic_dev.o

(gcc version 9.2.1, amd64)

Link: https://lore.kernel.org/r/20190906163945.3889-1-colin.king@canonical.com


Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>