tests: Fix warnings
This fixes warnings that are raised by missing includes, missing casts,
missing return statements, using printf %lu with uint64_t, and unused
symbols.
diff --git a/tests/smscb/smscb_test.c b/tests/smscb/smscb_test.c
index e10e12d..5925f69 100644
--- a/tests/smscb/smscb_test.c
+++ b/tests/smscb/smscb_test.c
@@ -21,6 +21,7 @@
#include <osmocom/gsm/protocol/gsm_03_41.h>
#include <stdio.h>
+#include <arpa/inet.h>
static uint8_t smscb_msg[] = { 0x40, 0x10, 0x05, 0x0d, 0x01, 0x11 };