obexd: Fix memory leak when loading plugins

On failure to open plugin directory, memory allocated to 'patterns'
and 'excludes' is not being freed, and the following memory leak is
logged:

Direct leak of 28 byte(s) in 1 object(s) allocated from:
    #0 0xb6aa1c49 in malloc (/usr/lib/liblsan.so+0x9c49)
    #1 0xb6976e89 in g_malloc (/lib/libglib-2.0.so.0+0x3ae89)
    #2 0xb69886f1 in g_strsplit_set (/lib/libglib-2.0.so.0+0x4c6f1)
    #3 0xb6f82f3b in plugin_init (/usr/libexec/bluetooth/obexd+0x20f3b)
    #4 0xb6f70dc9 in main (/usr/libexec/bluetooth/obexd+0xedc9)
diff --git a/obexd/src/plugin.c b/obexd/src/plugin.c
index 7d971b6..a1962b9 100644
--- a/obexd/src/plugin.c
+++ b/obexd/src/plugin.c
@@ -138,8 +138,11 @@
 	DBG("Loading plugins %s", PLUGINDIR);
 
 	dir = g_dir_open(PLUGINDIR, 0, NULL);
-	if (!dir)
+	if (!dir) {
+		g_strfreev(patterns);
+		g_strfreev(excludes);
 		return FALSE;
+	}
 
 	while ((file = g_dir_read_name(dir)) != NULL) {
 		struct obex_plugin_desc *desc;