x86/efi: Fix reboot_mode when EFI runtime services are disabled

When EFI runtime services are disabled, for example by the "noefi"
kernel cmdline parameter, the reboot_type could still be set to
BOOT_EFI causing reboot to fail.

Fix this by checking if EFI runtime services are enabled.

Signed-off-by: Stefan Assmann <sassmann@kpanic.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170724122248.24006-1-sassmann@kpanic.de
[ Fixed 'not disabled' double negation. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/reboot.c

@@ -471,12 +471,12 @@ static int __init reboot_init(void)
 
 	/*
 	 * The DMI quirks table takes precedence. If no quirks entry
-	 * matches and the ACPI Hardware Reduced bit is set, force EFI
-	 * reboot.
+	 * matches and the ACPI Hardware Reduced bit is set and EFI
+	 * runtime services are enabled, force EFI reboot.
 	 */
 	rv = dmi_check_system(reboot_dmi_table);
 
-	if (!rv && efi_reboot_required())
+	if (!rv && efi_reboot_required() && !efi_runtime_disabled())
 		reboot_type = BOOT_EFI;
 
 	return 0;