qa: resolve compiler warnings

-Wall flags this:

make  test_api test_filter
make[1]: Entering directory `/home/jengelh/code/libnetfilter_conntrack/qa'
  CC     test_api.o
test_api.c:16:8: warning: return type defaults to "int"
test_api.c: In function "eval_sigterm":
test_api.c:23:18: warning: too many arguments for format
test_api.c: In function "main":
test_api.c:55:2: warning: implicit declaration of function "fork"
test_api.c:34:22: warning: unused variable "h"
test_api.c:102:1: warning: control reaches end of non-void function
test_api.c: In function "eval_sigterm":
test_api.c:29:1: warning: control reaches end of non-void function
  CCLD   test_api
  CC     test_filter.o
test_filter.c: In function "main":
test_filter.c:58:4: warning: implicit declaration of function "inet_addr"
test_filter.c:74:2: warning: implicit declaration of function "strerror"
test_filter.c:74:2: warning: format "%s" expects type ‘char *’, but argument 3 has type ‘int’
test_filter.c:75:1: warning: control reaches end of non-void function
  CCLD   test_filter

make[1]: Leaving directory `/home/jengelh/code/libnetfilter_conntrack/qa'

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

1 files changed, 5 insertions, 1 deletions

diff --git a/qa/test_filter.c b/qa/test_filter.c
index 35fdbec..7877819 100644
--- a/qa/test_filter.c
+++ b/qa/test_filter.c
@@ -3,6 +3,9 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <arpa/inet.h>
 #include <errno.h>
 
 #include <libnetfilter_conntrack/libnetfilter_conntrack.h>
@@ -23,7 +26,7 @@ static int event_cb(enum nf_conntrack_msg_type type,
 	return NFCT_CB_CONTINUE;
 }
 
-int main()
+int main(void)
 {
 	int i, ret;
 	struct nfct_handle *h;
@@ -72,4 +75,5 @@ int main()
 
 	ret = nfct_catch(h);
 	printf("test ret=%d (%s)\n", ret, strerror(errno));
+	return EXIT_SUCCESS;
 }