include/queue: Create data file when queue is created

include/queue: Create data file when queue is created

The data file that contains the queue data is not created when a
queue is created, but rather when data is inserted into the queue.
This causes issues in applications that use queues to share between
users because they need so set permissions on the entire queue at
the time of initialization. However, because the data file is not
created at that time, its permissions cannot be set.

This commit modifies `queue_init()' so that the data file is created
together with the queue.