mediacontrol_util.c: better safe than sorry, specify the malloc unit.

src/control/mediacontrol_util.c

@@ -212,7 +212,7 @@ mediacontrol_RGBPicture__alloc( int datasize )
         return NULL;
 
     pic->size = datasize;
-    pic->data = ( char* )malloc( datasize );
+    pic->data = ( char* )malloc( datasize * sizeof( char ) );
     return pic;
 }