core: explicitly compare pointers to NULL

This patch was generated by the following semantic patch
(http://coccinelle.lip6.fr/)

// <smpl>
@fix disable is_null,isnt_null1@
expression *E;
@@

- !E
+ E == NULL
// </smpl>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/main.c b/src/main.c
index eca008ed..87fb0ab8 100644
--- a/src/main.c
+++ b/src/main.c
@@ -214,7 +214,7 @@ int main(int argc, char **argv)
 	dbus_error_init(&error);
 
 	conn = g_dbus_setup_bus(DBUS_BUS_SYSTEM, OFONO_SERVICE, &error);
-	if (!conn) {
+	if (conn == NULL) {
 		if (dbus_error_is_set(&error) == TRUE) {
 			ofono_error("Unable to hop onto D-Bus: %s",
 					error.message);