dccp ccid-3: Fix RFC reference

Thanks to Wei and Arnaldo for pointing out the correct
new reference for CCID-3.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/dccp/ccids/Kconfig

@@ -29,7 +29,7 @@ config IP_DCCP_CCID3
 	  http://www.ietf.org/rfc/rfc4342.txt
 
 	  The TFRC congestion control algorithms were initially described in
-	  RFC 5448.
+	  RFC 5348.
 
 	  This text was extracted from RFC 4340 (sec. 10.2),
 	  http://www.ietf.org/rfc/rfc4340.txt