When sending TX packets, the meta descriptor can be all zeroes
as no meta information is required (as in XDP).

This patch removes the validity check, as when
`disable_meta_caching` is enabled, such TX packets will be
dropped otherwise.

Fixes: 0e3a3f6d ("net: ena: support new LLQ acceleration mode")
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://lore.kernel.org/r/20231211062801.27891-5-darinzon@amazon.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>