lib/remote: Add arguments to internal OstreeRemote constructor

Add a name argument to the internal OstreeRemote constructor,
since this member (and several derived from it) is non-nullable,
and hence must always be set at construction time.

This changes the only call sites of the constructor to use the new API,
which is internal.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Closes: #875
Approved by: cgwalters

src/libostree/ostree-remote-private.h

@@ -46,7 +46,7 @@ struct OstreeRemote {
 };
 
 G_GNUC_INTERNAL
-OstreeRemote *ostree_remote_new (void);
+OstreeRemote *ostree_remote_new (const gchar *name);
 
 G_GNUC_INTERNAL
 OstreeRemote *ostree_remote_new_from_keyfile (GKeyFile    *keyfile,