ata_eh_autopsy() used to directly assign determined action mask to
ehc->i.action thus overriding actions set by some of nested analyze
functions.  This patch makes ata_eh_autopsy() add action masks just as
it's done in other places.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>