Fixed doxygen warning

src/sound/mad.cpp

@@ -190,11 +190,11 @@ local enum mad_flow MAD_error(void* user __attribute__((unused)),
 /**
 **  Read one frame from mad decoder.
 **
-**  @param decoder  Decoder
-**  @param buf      Buffer to write data to
-**  @param len      Length of the buffer
+**  @param sample  Sample
+**  @param buf     Buffer to write data to
+**  @param len     Length of the buffer
 **
-**  @return         Number of bytes read
+**  @return        Number of bytes read
 */
 local int MadRead(Sample *sample, unsigned char* buf, int len)
 {

src/video/sprite.cpp

@@ -451,7 +451,7 @@ global Graphic* LoadSprite(const char* name, int width, int height)
 /**
 **  Make shadow sprite
 **
-**  @param graphic  pointer to object
+**  @param g  pointer to object
 **
 **  @todo FIXME: 32bpp
 */