doc: fix tag for inner RSS feature

doc: fix tag for inner RSS feature

This patch fixes a wrong tag in guides/nics/features.rst.
The features tags should be, according to the
"Features Overview" section in this doc, one of the following:
"uses", "implements", "provides", or "related".
Hence in Inner RSS section, it should be "uses"
instead of "users".

Fixes: d0a87d9aa8de ("doc: update mlx5 guide on tunnel offloading")
Cc: stable@dpdk.org
Signed-off-by: Rami Rosen <ramirose@gmail.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>