mxgrub: use $KERNEL_PARAMETER everywhere

The variable $KERNEL_PARAMETER is supposed to be used everywhere a
kernel command line is build. One site was overlooked, so use it there,
too. Also remove ttyS0 from KERNEL_PARAMETER, which doesn't work.

mxgrub/mxgrub

@@ -239,7 +239,7 @@ sub scan_mariux {
 	}
 }
 
-our $KERNEL_PARAMETER="ro crashkernel=512M console=ttyS0,115200n8 console=ttyS1,115200n8 console=tty0 init=/bin/systemd audit=0";
+our $KERNEL_PARAMETER="ro crashkernel=512M console=ttyS1,115200n8 console=tty0 init=/bin/systemd audit=0";
 
 sub update_grub_cfg {
 	my $kernellist='';
@@ -248,7 +248,7 @@ sub update_grub_cfg {
 
 	for my $label (@MARIUX) {
 		my $image=label_to_image($label);
-		$kernellist.="\tmenuentry \"$label\" --unrestricted { save_env chosen ; linux /boot/$image crashkernel=256M root=LABEL=root ro console=ttyS1,115200n8 console=tty0 init=/bin/systemd audit=0 ; initrd /boot/grub/initramfs.igz }\n";
+		$kernellist.="\tmenuentry \"$label\" --unrestricted { save_env chosen ; linux /boot/$image root=LABEL=root $KERNEL_PARAMETER ; initrd /boot/grub/initramfs.igz }\n";
 	}
 
 	my $GRUB_CFG_NEW=<<"EOF";