ice: fix potential NULL pointer deref in error path of ice_set_ringparam()

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

ice: fix potential NULL pointer deref in error path of ice_set_ringparam()

ice_set_ringparam nullifies tstamp_ring of temporary tx_rings, without clearing ICE_TX_RING_FLAGS_TXTIME bit. When ICE_TX_RING_FLAGS_TXTIME is set and the subsequent ice_setup_tx_ring() call fails, a NULL pointer dereference could happen in the unwinding sequence:

ice_clean_tx_ring() -> ice_is_txtime_cfg() == true (ICE_TX_RING_FLAGS_TXTIME is set) -> ice_free_tx_tstamp_ring() -> ice_free_tstamp_ring() -> tstamp_ring->desc (NULL deref)

Clear ICE_TX_RING_FLAGS_TXTIME bit to avoid the potential issue.

Note that this potential issue is found by manual code review. Compile test only since unfortunately I don't have E830 devices.