When DualBoot mechanism is enabled and an update is pending,
the boot script needs to change certain variables and save the
environment.
The regular boot script already changes a number of variables,
such as 'extra_bootargs' and 'overlays' by appending strings to
the already existing values. Saving the envionment may make these
grow endlessly with each iteration of the boot script.
For this reason, move the DualBoot check as the first thing in
the script, save the environment if needed, and then continue
with the normal flow, that changes variables before booting
but doesn't save them.
On certain scripts, this allows us to get rid of some instructions
for resetting the overlays variable.
Signed-off-by: Hector Palacios <hector.palacios@digi.com>
05d21a1310