Add UEFI check; modify check loop

checks/internet.check

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-ping -c 1 archlinux.org 2>/tmp/arch-maride-flavour_checks_error.log 1>/tmp/arch-maride-flavour_checks_out.log
+ping -c 1 archlinux.org 2>/tmp/arch-maride-flavour_checks_internet_error.log 1>/tmp/arch-maride-flavour_checks_internet_out.log
 return=$?
 
 if [ "$return" -eq 0 ]; then

checks/uefi.check

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+ls /sys/firmware/efi/efivars 2>/tmp/arch-maride-flavour_checks_uefi_error.log 1>/tmp/arch-maride-flavour_checks_uefi_out.log
+return=$?
+
+if [ "$return" -eq 0 ]; then
+	exit 0
+else
+	echo "~> This doesn't seem to be an UEFI boot. Please boot UEFI."
+	exit 1
+fi