shift the cmdline argument after determining
there is atleast 1 argument to shift otherwise
it ends up in error when no argument is specified
(From OE-Core rev: 4cd306ab0c9404a31f38c7e5fb67fe32fdca3d4b)
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>