-EINVAL will be returned even though the "adapter" argument is perfectly
valid.
Change this so that we only return -EINVAL if the provided string is
invalid. If the host does not implement a ->host_reset function we'll
return -EOPNOTSUPP.
[mkp: tweaked patch description]
Signed-off-by: weiping zhang <zhangweiping@didichuxing.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>