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

src/libstrongswan/crypto/prf_plus.h

@@ -38,8 +38,8 @@ struct prf_plus_t {
 	 * @param buffer	pointer where the generated bytes will be written
 	 * @return			TRUE if bytes generated successfully
 	 */
-	__attribute__((warn_unused_result))
-	bool (*get_bytes) (prf_plus_t *this, size_t length, u_int8_t *buffer);
+	bool (*get_bytes)(prf_plus_t *this, size_t length,
+					  u_int8_t *buffer) __attribute__((warn_unused_result));
 
 	/**
 	 * Allocate pseudo random bytes.
@@ -48,13 +48,13 @@ struct prf_plus_t {
 	 * @param chunk		chunk which will hold generated bytes
 	 * @return			TRUE if bytes allocated successfully
 	 */
-	__attribute__((warn_unused_result))
-	bool (*allocate_bytes) (prf_plus_t *this, size_t length, chunk_t *chunk);
+	bool (*allocate_bytes)(prf_plus_t *this, size_t length,
+						   chunk_t *chunk) __attribute__((warn_unused_result));
 
 	/**
 	 * Destroys a prf_plus_t object.
 	 */
-	void (*destroy) (prf_plus_t *this);
+	void (*destroy)(prf_plus_t *this);
 };
 
 /**