efi_loader: factor out efi_check_register_notify_event()

The code to check if a registration key is a valid key returned by
RegisterProtocolNotify() can be reused. So let us factor it out into a new
function efi_check_register_notify_event().

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
1 file changed