In `efidebug boot add iPXE scsi 0:1 snp-arm64.efi --foo` a parameter is
missing. Hence the command should not silently return as if everything were
ok but should display the usage info.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Reviewed-by: Alexander Graf <agraf@csgraf.de>