daemon: Don't leak mountable_name
daemon: Don't leak mountable_name

If the daemon code allocates a unique mountable_name, later this string
is lost. Store and free it properly to remove the memory leak.

https://bugzilla.gnome.org/show_bug.cgi?id=757901

Signed-off-by: Dmitry Eremin-Solenikov <b6edad08270b2e4ffbcb0879e25a0e29a48c5275@gmail.com>
[79f5abba52d1903ec2619f9259574478b3551c8f@redhat.com: commit message modification]
Signed-off-by: Ondrej Holy <79f5abba52d1903ec2619f9259574478b3551c8f@redhat.com>

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