drivers/scsi/ufs: fix evaluation of task_failed status

drivers/scsi/ufs: fix evaluation of task_failed status

Else FAILED would be set even if task_result was originally equal to
UPIU_TASK_MANAGEMENT_FUNC_SUCCEEDED.

Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Venkatraman S <svenkatr@ti.com>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Acked-by: Santosh Y <santoshsy@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>