libata: Fix sysfs documentation bug

forced_unqueued indicates that a drive's queued DSM support is
broken. Update sysfs ABI documentation accordingly.

Reported-by: Christoph Hellwig <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>
Signed-off-by: Tejun Heo <[e-mail]>

Documentation/ABI/testing/sysfs-ata

···
 	unsupported:		Drive does not support DSM TRIM
 	unqueued:		Drive supports unqueued DSM TRIM only
 	queued:			Drive supports queued DSM TRIM
-	forced_unqueued:	Drive's unqueued DSM support is known to be
+	forced_unqueued:	Drive's queued DSM support is known to be
 				buggy and only unqueued TRIM commands
 				are sent