extensions: libxt_NFLOG: fix typo

The deprecation warning for `--nflog-range` contains a spelling mistake.
Fix it.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
diff --git a/extensions/libxt_NFLOG.c b/extensions/libxt_NFLOG.c
index 6137a68..7a12e5a 100644
--- a/extensions/libxt_NFLOG.c
+++ b/extensions/libxt_NFLOG.c
@@ -74,7 +74,7 @@
 
 	if (cb->xflags & F_RANGE)
 		fprintf(stderr, "warn: --nflog-range has never worked and is no"
-			" longer supported, please use --nflog-size insted\n");
+			" longer supported, please use --nflog-size instead\n");
 
 	if (cb->xflags & F_SIZE)
 		info->flags |= XT_NFLOG_F_COPY_LEN;