Fix UDP acronym

It's 'User', not 'Unreliable'.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/HOWTO b/HOWTO
index cdff07a..aa06fd5 100644
--- a/HOWTO
+++ b/HOWTO
@@ -1327,7 +1327,7 @@
 [net] proto=str	The network protocol to use. Accepted values are:
 
 			tcp	Transmission control protocol
-			udp	Unreliable datagram protocol
+			udp	User datagram protocol
 			unix	UNIX domain socket
 
 		When the protocol is TCP or UDP, the port must also be given,