i386: convert hardware exception 18 to an interrupt gate

Handle machine check exception with interrupt initially off.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/entry_32.S

@@ -1019,7 +1019,7 @@ ENTRY(machine_check)
 	RING0_INT_FRAME
 	pushl $0
 	CFI_ADJUST_CFA_OFFSET 4
-	pushl machine_check_vector
+	pushl $do_machine_check
 	CFI_ADJUST_CFA_OFFSET 4
 	jmp error_code
 	CFI_ENDPROC