Fix tarfs again.
 [rsc] --rw-rw-r-- M 155802 glenda sys 2703 Oct 20 20:50 sys/src/cmd/tapefs/tarfs.c
	/n/sourcesdump/2005/1020/plan9/sys/src/cmd/tapefs/tarfs.c:58,67 - 
	/n/sourcesdump/2005/1021/plan9/sys/src/cmd/tapefs/tarfs.c:58,69
	  		/* the mode test is ugly but sometimes necessary */
	  		if (dblock.dbuf.linkflag == '5'
	  		|| (f.mode&0170000) == 040000
	- 		||  strrchr(dblock.dbuf.name, '\0')[-1] == '/')
	+ 		||  strrchr(dblock.dbuf.name, '\0')[-1] == '/'){
	  			f.mode |= DMDIR;
	+ 			f.size = 0;
	+ 		}
	  		f.mode &= DMDIR|0777;
	- 		linkflg = dblock.dbuf.linkflag=='5' || dblock.dbuf.linkflag=='1';
	+ 		linkflg = dblock.dbuf.linkflag=='s' || dblock.dbuf.linkflag=='1';
	  		isabs = dblock.dbuf.name[0]=='/';
	  		if (chksum != checksum()){
	  			fprint(1, "bad checksum on %.28s\n", dblock.dbuf.name);
 [sys] --rwxrwxr-x M 155802 glenda sys 94363 Oct 20 23:17 386/bin/fs/tarfs
	/sys/src/cmd/tapefs/tarfs.c:populate