udev-extraconf/mount.sh: save mount name in our tmp filecache

udev-extraconf/mount.sh: save mount name in our tmp filecache

Doing this will allow to fetch the exact name created by the
auto-mounter during the remove action where depending on the
scenario utilities such as the blkid might not be usable due
to actual device not being present on the system.

Signed-off-by: Awais Belal <awais_belal@mentor.com>
Signed-off-by: Muhammad Hamza <muhammad_hamza@mentor.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>