x86: fix section mismatch warning - apic_flat

Impact: cleanup only, no functionality changed

WARNING: vmlinux.o(.data+0xbe08): Section mismatch in reference from the variable apic_flat to the function .init.text:flat_acpi_madt_oem_check()
The variable apic_flat references
the function __init flat_acpi_madt_oem_check()

This is harmless, because the .acpi_madt_oem_check is only called
during init time. But we keep the function pointer around in a .data
function pointer template, so it's better we do not keep that stale
- so mark this function non-__init.
Signed-off-by: NMarcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/genapic_flat_64.c

@@ -25,7 +25,7 @@
 #include <acpi/acpi_bus.h>
 #endif
 
-static int __init flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 {
 	return 1;
 }