udisks2: Abort mount operation if volume is unlocked
udisks2: Abort mount operation if volume is unlocked

Mount operation for encrypted volumes consists from two udisks2 calls
(unlock and mount). Volume monitor is able to mount already unlocked
volumes. However password prompt doesn't disappear if the volume is
unlocked externally and any reaction causes mount operation failure.
The volume may be unlocked externally by e.g. project Tang, see
https://github.com/latchset/tang for more details. Abort mount
operation and continue with mounting in such situations.

https://bugzilla.gnome.org/show_bug.cgi?id=763890

gicmo/gvfs,gicmo/gvfs,gicmo/gvfs,gicmo/gvfs