doxygen: enable AUTOBRIEF, drop \brief

Especially for short descriptions, it is annoying to have to type \brief for
every single API doc.

Drop all \brief and enable the AUTOBRIEF feature of doxygen, which always takes
the first sentence of an API doc as the brief description.

Change-Id: I11a8a821b065a128108641a2a63fb5a2b1916e87
diff --git a/include/osmocom/vty/telnet_interface.h b/include/osmocom/vty/telnet_interface.h
index e939ec7..bca9156 100644
--- a/include/osmocom/vty/telnet_interface.h
+++ b/include/osmocom/vty/telnet_interface.h
@@ -31,17 +31,17 @@
 
 /*! \file telnet_interface.h */
 
-/*! \brief A telnet connection */
+/*! A telnet connection */
 struct telnet_connection {
-	/*! \brief linked list header for internal management */
+	/*! linked list header for internal management */
 	struct llist_head entry;
-	/*! \brief private data pointer passed through */
+	/*! private data pointer passed through */
 	void *priv;
-	/*! \brief filedsecriptor (socket ) */
+	/*! filedsecriptor (socket ) */
 	struct osmo_fd fd;
-	/*! \brief VTY instance associated with telnet connection */
+	/*! VTY instance associated with telnet connection */
 	struct vty *vty;
-	/*! \brief logging target associated with this telnet connection */
+	/*! logging target associated with this telnet connection */
 	struct log_target *dbg;
 };