Reboot dialog fixes

Reboot dialog could not show up if the PowerMenu has not been called yet.
Also respect "show reboot on Lockscreen" setting of PowerMenu.

PS2: Formatting fix

Change-Id: If544575f0716be70b6a48d32ee273de0188c47a5
Signed-off-by: Gergely Szell (sethyx) <szell@hu.ibm.com>