filetable: Don't bother pre-clearing for filetable::copy
filetable: Don't bother pre-clearing for filetable::copy

Previously, the constructor would clear the file table, only to have copy
overwrite everything that it cleared.

aclements/sv6,bowlofstew/sv6,aclements/sv6,bowlofstew/sv6,aclements/sv6,bowlofstew/sv6,bowlofstew/sv6,aclements/sv6,bowlofstew/sv6,aclements/sv6