There are two ways to check firmware version in ESXi:
The first is to run the /usr/lib/vmware/vm-support/bin/swfw.sh then search the hardware you are looking for.
The second to to list the device, then find the detailed info.
For FC HBA:
ls /proc/scsi/qla2xxx/* | xargs head –2
For network adapters:
esxcli network nic list
ethtool –I vmnic?