Prevent a segfault on alpha and any other arch that doesn't always get
zero-initialized automatics.  Frankly the code in this segment looks
pretty broken to me, but I'm just fixing the segfault...

07 Feb 2004 agriffis

--- id3v2.cpp	2004-05-04 20:30:15.000000000 +0200
+++ id3v2.cpp.alpha	2004-08-29 16:13:08.848513320 +0200
@@ -423,7 +423,7 @@
         {
           // check if there is a total track number and if we only have 
           // the track number for this file.  In this case combine them.
-          char *currentTrackNum, *newTrackNum;
+          char *currentTrackNum, *newTrackNum = NULL;
 
           if (pFrame != NULL) 
           {