RDMA/restrack: Fix potential invalid address access

In the Linux kernel, the following vulnerability has been resolved: RDMA/restrack: Fix potential invalid address access struct rdma_restrack_entry's kern_name was set to KBUILD_MODNAME in ib_create_cq(), while if the module exited but forgot del this rdma_restrack_entry, it would cause a invalid address access in rdma_restrack_clean() when print the owner of this rdma_restrack_entry. These code is used to help find one forgotten PD release in one of the ULPs. But it is not needed anymore, so delete them.