The /usr/src path is commonly used in kernel development and should come from the target

Signed-off-by: David Greaves <david@dgreaves.com>
Also trim tabs from the package name.

Signed-off-by: Marko Saukko <marko.saukko@jollamobile.com>
Make sure that bind mounts are private before umounting.

On some systems the bind mounts are shared by default which makes
the sdk umount also umount the host system mounts.

Signed-off-by: Marko Saukko <marko.saukko@jollamobile.com>