BUGFIX: bk abort with empty BitKeeper/tmp/patch
BUGFIX: bk abort with empty BitKeeper/tmp/patch

It sends crap to unlink().

bk: 4a6f77bd_wSDE5NK_vtOOWxexgPbAQ
bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper