|WARNING| [v2] net/bnxt: fix aliasing in firmware command writes

[Alexander Goodkind]

> On the last iteration when i + 4 > msg_len, only msg_len - i bytes
> are copied.

The copy length is sizeof(request_word), so memcpy initializes the
entire uint32_t before rte_write32(). It does not shorten the copy
based on msg_len. The previous pointer dereference also read a full
uint32_t.

> Missing release notes update

Comparable fixes, including the enic aliasing fix [1] and the checksum
memcpy fix [2], did not include release-note entries. I followed that
precedent here, but I can add a release-note entry if the maintainers
would prefer one.

[1] https://github.com/DPDK/dpdk/commit/7895d17cf41094cb7d5ad67f484dd492f5a643bf
[2] https://github.com/DPDK/dpdk/commit/1c9a7fba5c90e0422b517404499ed106f647bcff