docs: networking: Align documentation with behavior change

Following commit 9f7e8fbb ("net/mlx5: offset comp irq index in name by one"),
which fixed the index in IRQ name to start once again from 0, we change
the documentation accordingly.

Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Link: https://patch.msgid.link/20240815142343.2254247-1-tariqt@nvidia.com


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