Avoid problems with Doxygen by adding warn_unused_result attribute at the end of method signatures

src/libstrongswan/crypto/rngs/rng.h

@@ -56,8 +56,8 @@ struct rng_t {
 	 * @param buffer	pointer where the generated bytes will be written
 	 * @return			TRUE if bytes successfully written
 	 */
-	__attribute__((warn_unused_result))
-	bool (*get_bytes) (rng_t *this, size_t len, u_int8_t *buffer);
+	bool (*get_bytes)(rng_t *this, size_t len,
+					  u_int8_t *buffer) __attribute__((warn_unused_result));
 
 	/**
 	 * Generates random bytes and allocate space for them.
@@ -66,13 +66,13 @@ struct rng_t {
 	 * @param chunk		chunk which will hold generated bytes
 	 * @return			TRUE if allocation succeeded
 	 */
-	__attribute__((warn_unused_result))
-	bool (*allocate_bytes) (rng_t *this, size_t len, chunk_t *chunk);
+	bool (*allocate_bytes)(rng_t *this, size_t len,
+						   chunk_t *chunk) __attribute__((warn_unused_result));
 
 	/**
 	 * Destroys a rng object.
 	 */
-	void (*destroy) (rng_t *this);
+	void (*destroy)(rng_t *this);
 };
 
 /**