*** Submitted as 8dfddf14ba55 ***
vac: fix segfault on DMSYMLINK or DMDEVICE
Fix segfault when the first archived file is DMSYMLINK or DMDEVICE.
Reinitialize the buffer to zero before calling readlink.
R=rsc
CC=plan9port.codebot
http://codereview.appspot.com/5500097
Committer: Russ Cox <rsc@swtch.com>