runqemu-extract-sdk: normalize paths to improve output

runqemu-extract-sdk: normalize paths to improve output

Previously, we would have output like below from runqemu-extract-sdk.

    Creating directory /home/chenqi/poky/build-systemd/./nfs-root

Normalize paths for runqemu-extract-sdk so that we have output like below.

    Creating directory /home/chenqi/poky/build-systemd/nfs-root

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>