vsock: always call vsock_init_tables()

vsock: always call vsock_init_tables()

Although CONFIG_VSOCKETS_DIAG depends on CONFIG_VSOCKETS,
vsock_init_tables() is not always called, it is called only
if other modules call its caller. Therefore if we only
enable CONFIG_VSOCKETS_DIAG, it would crash kernel on uninitialized
vsock_bind_table.

This patch fixes it by moving vsock_init_tables() to its own
module_init().

Fixes: 413a4317aca7 ("VSOCK: add sock_diag interface")
Reported-by: syzkaller bot
Cc: Stefan Hajnoczi <[email protected]>
Cc: Jorgen Hansen <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Reviewed-by: Stefan Hajnoczi <[email protected]>
Signed-off-by: David S. Miller <[email protected]>