iproute2: spelling: noptmudisc -> nopmtudisc

Signed-off-by: Richard Godbee <richard@godbee.net>
diff --git a/ip/link_iptnl.c b/ip/link_iptnl.c
index 394254d..d5324f8 100644
--- a/ip/link_iptnl.c
+++ b/ip/link_iptnl.c
@@ -233,7 +233,7 @@
 	}
 
 	if (ttl && pmtudisc == 0) {
-		fprintf(stderr, "ttl != 0 and noptmudisc are incompatible\n");
+		fprintf(stderr, "ttl != 0 and nopmtudisc are incompatible\n");
 		exit(-1);
 	}