Update comment in mediaplayer.h.

When sending a MEDIA_INFO message, the second integer is supposed
to be an "info" code instead of an "error" code.
diff --git a/include/media/mediaplayer.h b/include/media/mediaplayer.h
index 513ffe1..0355c16 100644
--- a/include/media/mediaplayer.h
+++ b/include/media/mediaplayer.h
@@ -75,7 +75,7 @@
 // 'notify' is invoked with the following:
 //   'msg' is set to MEDIA_INFO.
 //   'ext1' should be a value from the enum media_info_type.
-//   'ext2' contains an implementation dependant error code to provide
+//   'ext2' contains an implementation dependant info code to provide
 //          more details. Should default to 0 when not used.
 //
 // The codes are distributed as follow: