If the spec file already exist, and has not been stored into pseudo's files.db,
it maybe cause rpmbuild src.rpm fail, so remove it before doing rpmbuild src.rpm.
(From OE-Core rev: 760af902a98b350a2f1f3203fa0096965924a83d)
Signed-off-by: Bian Naimeng <biannm@cn.fujitsu.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>