osmux: Fix the VTY online help in the osmux command

This should fix most of:

Documentation error (missing docs):
<command id='osmux (on|off)'>
        <param name='off' doc='(null)' />

Documentation error (missing docs):
<command id='osmux batch-factor &lt;1-4&gt;'>
        <param name='&lt;1-4&gt;' doc='(null)' />

Documentation error (missing docs):
<command id='osmux (on|off)'>
        <param name='off' doc='(null)' />

Documentation error (missing docs):
<command id='osmux (on|off)'>
        <param name='off' doc='(null)' />

Documentation error (missing docs):
<command id='osmux batch-factor &lt;1-4&gt;'>
        <param name='&lt;1-4&gt;' doc='(null)' />
diff --git a/openbsc/src/libmgcp/mgcp_vty.c b/openbsc/src/libmgcp/mgcp_vty.c
index e9b7d12..1f8a63a 100644
--- a/openbsc/src/libmgcp/mgcp_vty.c
+++ b/openbsc/src/libmgcp/mgcp_vty.c
@@ -1068,7 +1068,7 @@
 	return CMD_SUCCESS;
 }
 
-#define OSMUX_STR "RTP multiplexing"
+#define OSMUX_STR "RTP multiplexing\n"
 DEFUN(cfg_mgcp_osmux,
       cfg_mgcp_osmux_cmd,
       "osmux (on|off)",