Retry ruleset dump when kernel returns EAGAIN.

Bugzilla #104
diff --git a/libiptc/libiptc.c b/libiptc/libiptc.c
index b7bf785..277ca0f 100644
--- a/libiptc/libiptc.c
+++ b/libiptc/libiptc.c
@@ -1226,7 +1226,7 @@
 			return NULL;
 	}
 	sockfd_use++;
-
+retry:
 	s = sizeof(info);
 
 	strcpy(info.name, tablename);
@@ -1279,6 +1279,9 @@
 	return h;
 error:
 	TC_FREE(&h);
+	/* A different process changed the ruleset size, retry */
+	if (errno == EAGAIN)
+		goto retry;
 	return NULL;
 }