RDMA/irdma: Initialize free_qp completion before using it

In the Linux kernel, the following vulnerability has been resolved:

RDMA/irdma: Initialize free_qp completion before using it

In irdma_create_qp, if ib_copy_to_udata fails, it will call

irdma_destroy_qp to clean up which will attempt to wait on

the free_qp completion, which is not initialized yet. Fix this

by initializing the completion before the ib_copy_to_udata call.