net/e1000: fix memory barrier usage in Tx
net/e1000: fix memory barrier usage in Tx

Use rte_cio_wmb instead of rte_wmb when writing TX descriptor since it's
CIO memory.
Replace rte_io_wmb and E1000_PCI_REG_WRITE_RELAXED with
E1000_PCI_REG_WRITE since it has rte_io_wmb inside, which will be more
clear.

Fixes: 1fc9701238ed ("net/e1000: fix i219 hang on reset/close")
Cc: stable@dpdk.org

Signed-off-by: Xiao Zhang <e866cfeaa4d3c2b680d7d7e13894b33652b9aeaf@intel.com>
Reviewed-by: Gavin Hu <207ee22c2cf71e20c5b5df8395050c07c07d8709@arm.com>
Reviewed-by: Xiaolong Ye <c7d6fc2f7e22da80deb234d523238b510a8c0f08@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk