Documentation: bareudp: Corrected description of bareudp module.

Removed redundant words.

Fixes: 571912c6

 ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>