32vfs: remove unused buffer
 [rsc] --rw-rw-r-- M 1942060 glenda sys 3899 Feb 28 11:42 sys/src/cmd/tapefs/32vfs.c
	/n/sourcesdump/2006/0228/plan9/sys/src/cmd/tapefs/32vfs.c:52,58 - 
	/n/sourcesdump/2006/0301/plan9/sys/src/cmd/tapefs/32vfs.c:52,57
	  populate(char *name)
	  {
	  	Fileinf f;
	- 	uchar buf[MAXBLSIZE];
	  
	  	BLSIZE = 512;	/* 32v */
	  	if(blocksize){