service: fix the default return value for service_get_source()

diff --git a/src/service.c b/src/service.c
index ae08a39a27f1baed51e2a8f1da0554f6b0fcb321..c65301666f7b748d012bee7c150b628306b182dc 100644 (file)
--- a/src/service.c
+++ b/src/service.c
@@ -1549,7 +1549,7 @@ const char *
 service_get_source ( service_t *s )
 {
   if (s->s_source) return s->s_source(s);
-  return 0;
+  return NULL;
 }
 
 /*