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/strrb.h b/include/osmocom/core/strrb.h
index 7507cf4..2b4d89f 100644
--- a/include/osmocom/core/strrb.h
+++ b/include/osmocom/core/strrb.h
@@ -24,7 +24,7 @@
  */
 
 /*! \file strrb.h
- *  \brief Osmocom string ringbuffer handling routines
+ *  Osmocom string ringbuffer handling routines
  */
 
 #include <unistd.h>
@@ -33,14 +33,14 @@
 
 #include <osmocom/core/talloc.h>
 
-/*! \brief A structure representing an osmocom string ringbuffer */
+/*! A structure representing an osmocom string ringbuffer */
 
 #define RB_MAX_MESSAGE_SIZE 240
 struct osmo_strrb {
-	uint16_t start;		/*!< \brief index of the first slot */
-	uint16_t end;		/*!< \brief index of the last slot */
-	uint16_t size;		/*!< \brief max number of messages to store */
-	char **buffer;		/*!< \brief storage for messages */
+	uint16_t start;		/*!< index of the first slot */
+	uint16_t end;		/*!< index of the last slot */
+	uint16_t size;		/*!< max number of messages to store */
+	char **buffer;		/*!< storage for messages */
 };
 
 struct osmo_strrb *osmo_strrb_create(TALLOC_CTX * ctx, size_t rb_size);