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:
esxcfg-scsidevs –a
ls /proc/scsi/qla2xxx/* | xargs head –2
For network adapters:
esxcli network nic list
ethtool –I vmnic?
References:
Identifying the firmware of a Qlogic or Emulex FC HBA (1002413)
Determining Network/Storage firmware and driver version in ESXi/ESX 4.x and 5.x (1027206)
Jackie Chen's IT Workshop 