initrdscripts: make boot drive detection more generic
The init script that invokes install and install-efi scripts
passes the first parameter that identifies the boot drive but
in cases when this disk is labeled and kernel configurations
allow disk labeling under /run/media/ this would pass the disk
label.
The earlier implementation considered that the drive name will
be passed and in case the label is passed it fails and provides
the boot drive as an option for installation driver.
We now use a more generic approach to identify the boot drive
which can handle both drive name as well as label if passed.
Signed-off-by: Awais Belal <awais_belal@mentor.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
