cpumask: Remove IA64 definition of total_cpus now it's in core code

Impact: fix IA64 compile

Fortunately, they have exactly the same semantics.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

arch/ia64/kernel/acpi.c

@@ -202,7 +202,6 @@ char *__init __acpi_map_table(unsigned long phys_addr, unsigned long size)
                             Boot-time Table Parsing
    -------------------------------------------------------------------------- */
 
-static int total_cpus __initdata;
 static int available_cpus __initdata;
 struct acpi_table_madt *acpi_madt __initdata;
 static u8 has_8259;