feat(fwu): simplify the assert to check for fwu init

Simplify the assert to check if the FWU subsystem has been initialised
in the fwu_is_trial_run_state function.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Change-Id: I428668470ebd4b67e68777a62d5732cb96841ab9
1 file changed