libata-scsi: fix SET FEATURES "filtering" for ata_msense_caching()

Without this fix, the DRA bit of the caching mode page would not
be updated when the read look-ahead feature is toggled (e.g. with
`smartctl --set`), but will only be until, for example, the write
cache feature is touched.

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>