Fix com_init() in case arguments are given.

As the ->name field of struct afs_table was only initialized in the afs process,
com_init(), which gets forked from the server process, did not see the table
names and would segfault due to a NULL pointer dereference if table names
were given as arguments.

Fix it by initializing the ->name fields in the definition of the afs_tables array.

This bug was introduced in commit 53d503ce back in 2007...