net: qrtr: Allocate workqueue before kernel_bind

A null pointer dereference in qrtr_ns_data_ready() is seen if a client
opens a qrtr socket before qrtr_ns_init() can bind to the control port.
When the control port is bound, the ENETRESET error will be broadcasted
and clients will close their sockets. This results in DEL_CLIENT
packets being sent to the ns and qrtr_ns_data_ready() being called
without the workqueue being allocated.

Allocate the workqueue before setting sk_data_ready and binding to the
control port. This ensures that the work and workqueue structs are
allocated and initialized before qrtr_ns_data_ready can be called.

Fixes: 0c2204a4 ("net: qrtr: Migrate nameservice to kernel from userspace")
Signed-off-by: Chris Lew <clew@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>