This is an expected behavior, as the HP NMI module is not supported on HP ProLiant Gen8 and newer servers. The load failure does not fail the boot process, and no functionality is affected. The HP NMI module is included in the HP Custom Image, only to support the older generation of HP ProLiant servers.
HP provides a custom image, which includes a compatible NMI module, which logs information to the HP Integrated Management Log. Install the host using the HP Custom Image for ESXi 5.5, available at
VMware Downloads.