We're seeing "cmd" static libs being sometimes present and sometimes not.
The issue depends whether BUILD == TARGET so they're present for qemux86-64
on x86-64 hosts but not for qemux86-64 on an aarch64 system.
Add an extra deletion to make the files consistent between the different
hosts.
(From OE-Core rev: 6e652835814c389a826ad2d262ee26c14dfb48b5)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>