Fix flex for pam build

Change-Id: Ib33bc5b83e273c1a492e09226a45fe5e021dc35a
Remove core-image-minimal-initramfs error

Prevent execution of core-image-minimal-initramfs:do_rootfs in order to
remove a build error. This doesn't affect the image creation but is a
temporary workaround. The will need to be fixed properly in the future.

Signed-off-by: Kévin THIERRY <kevin.thierry@open.eurogiciel.org>
Merge branch 'master' of git.vannes:/srv/git/gitcache/github.com/eurogiciel-oss/poky