x86: fix section mismatch warning - apic_physflat

Impact: cleanup only, no functionality changed

WARNING: vmlinux.o(.data+0xbe88): Section mismatch in reference from the variable apic_physflat to the function .init.text:physflat_acpi_madt_oem_check()
The variable apic_physflat references
the function __init physflat_acpi_madt_oem_check()

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/genapic_flat_64.c

@@ -170,7 +170,7 @@ struct genapic apic_flat =  {
  * We cannot use logical delivery in this case because the mask
  * overflows, so use physical mode.
  */
-static int __init physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
+static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 {
 #ifdef CONFIG_ACPI
 	/*