net: ena: Fix XDP redirection error

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.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>