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/core/write_queue.h b/include/osmocom/core/write_queue.h
index 4e0fdf3..27d090d 100644
--- a/include/osmocom/core/write_queue.h
+++ b/include/osmocom/core/write_queue.h
@@ -34,21 +34,21 @@
 
 /*! write queue instance */
 struct osmo_wqueue {
-	/*! \brief osmocom file descriptor */
+	/*! osmocom file descriptor */
 	struct osmo_fd bfd;
-	/*! \brief maximum length of write queue */
+	/*! maximum length of write queue */
 	unsigned int max_length;
-	/*! \brief current length of write queue */
+	/*! current length of write queue */
 	unsigned int current_length;
 
-	/*! \brief actual linked list implementing the queue */
+	/*! actual linked list implementing the queue */
 	struct llist_head msg_queue;
 
-	/*! \brief call-back in case qeueue is readable */
+	/*! call-back in case qeueue is readable */
 	int (*read_cb)(struct osmo_fd *fd);
-	/*! \brief call-back in case qeueue is writable */
+	/*! call-back in case qeueue is writable */
 	int (*write_cb)(struct osmo_fd *fd, struct msgb *msg);
-	/*! \brief call-back in case qeueue has exceptions */
+	/*! call-back in case qeueue has exceptions */
 	int (*except_cb)(struct osmo_fd *fd);
 };