scsi: elx: libefc: Fix less than zero comparison of a unsigned int

The comparison of the u32 variable rc to less than zero always false
because it is unsigned. Fix this by making it an int.

Link: https://lore.kernel.org/r/20210616170401.15831-1-colin.king@canonical.com


Fixes: 202bfdff ("scsi: elx: libefc: FC node ELS and state handling")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Addresses-Coverity: ("Unsigned compared against 0")