Add optional check to do_populate_sdk() that verifies SDK sysroots don't
contain dangling or escaping symlinks before attempting to tar an archive.
Such links may fail a `tar -h` operation (-h => follow symlinks) or
archive the build system's files.
Set CHECK_SDK_SYSROOTS = "1" to enable this check.
Use case: The -h option may be set via SDKTAROPTS in some configurations
to create symlink-less SDK archives for Windows file systems.
Signed-off-by: Haris Okanovic <haris.okanovic@ni.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
