net: dsa: remove "inline" from dsa_user_netpoll_send_skb()

The convention is to not use "inline" functions in C files, and let the
compiler decide whether to inline or not.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240206112927.4134375-1-vladimir.oltean@nxp.com


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