Andy, the 5 step doesnt help u. In my start topic I have got this device, but mlnx soft think it doesnt modified. cause using rpms not modified for ur kernel.
u can check like this:
rpm -qa | grep rdma
librdmacm-1.0.21mlnx-OFED.3.0.1.5.2.x86_64
librdmacm-devel-1.0.21mlnx-OFED.3.0.1.5.2.x86_64
librdmacm-utils-1.0.21mlnx-OFED.3.0.1.5.2.x86_64
it was in ur software before add-kernel-support too. the way to check it - only no this messages in logs)