ipv4: Clean whitespaces in net/ipv4/Kconfig.

While going through net/ipv4/Kconfig cleanup whitespaces.
Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/Kconfig

@@ -77,7 +77,9 @@ config IP_FIB_TRIE
 	  LC-trie is described in:
 
 	  IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
- 	IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
+	  IEEE Journal on Selected Areas in Communications, 17(6):1083-1092,
+	  June 1999
+
 	  An experimental study of compression methods for dynamic tries
 	  Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
 	  http://www.nada.kth.se/~snilsson/public/papers/dyntrie2/