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/crypt/auth.h b/include/osmocom/crypt/auth.h
index 7a27f3b..af4ae15 100644
--- a/include/osmocom/crypt/auth.h
+++ b/include/osmocom/crypt/auth.h
@@ -10,14 +10,14 @@
 
 #include <osmocom/core/linuxlist.h>
 
-/*! \brief Authentication Type (GSM/UMTS) */
+/*! Authentication Type (GSM/UMTS) */
 enum osmo_sub_auth_type {
 	OSMO_AUTH_TYPE_NONE	= 0x00,
 	OSMO_AUTH_TYPE_GSM	= 0x01,
 	OSMO_AUTH_TYPE_UMTS	= 0x02,
 };
 
-/*! \brief Authentication Algorithm */
+/*! Authentication Algorithm */
 enum osmo_auth_algo {
 	OSMO_AUTH_ALG_NONE,
 	OSMO_AUTH_ALG_COMP128v1,
@@ -28,7 +28,7 @@
 	_OSMO_AUTH_ALG_NUM,
 };
 
-/*! \brief permanent (secret) subscriber auth data */
+/*! permanent (secret) subscriber auth data */
 struct osmo_sub_auth_data {
 	enum osmo_sub_auth_type type;
 	enum osmo_auth_algo algo;
@@ -61,19 +61,19 @@
 	uint32_t auth_types;	/*!< bitmask of OSMO_AUTH_TYPE_* */
 };
 
-/* \brief An implementation of an authentication algorithm */
+/* An implementation of an authentication algorithm */
 struct osmo_auth_impl {
 	struct llist_head list;
 	enum osmo_auth_algo algo; /*!< algorithm we implement */
 	const char *name;	/*!< name of the implementation */
 	unsigned int priority;	/*!< priority value (resp. othe implementations */
 
-	/*! \brief callback for generate authentication vectors */
+	/*! callback for generate authentication vectors */
 	int (*gen_vec)(struct osmo_auth_vector *vec,
 			struct osmo_sub_auth_data *aud,
 			const uint8_t *_rand);
 
-	/* \brief callback for generationg auth vectors + re-sync */
+	/* callback for generationg auth vectors + re-sync */
 	int (*gen_vec_auts)(struct osmo_auth_vector *vec,
 			    struct osmo_sub_auth_data *aud,
 			    const uint8_t *auts, const uint8_t *rand_auts,