octeontx2-pf: Fix transmit scheduler resource leak

In the Linux kernel, the following vulnerability has been resolved: octeontx2-pf: Fix transmit scheduler resource leak Inorder to support shaping and scheduling, Upon class creation Netdev driver allocates trasmit schedulers. The previous patch which added support for Round robin scheduling has a bug due to which driver is not freeing transmit schedulers post class deletion. This patch fixes the same.