fix cpumask build breakage on parisc

Commit 2d3854a37e8b767a51aba38ed6d22817b0631e33 ("cpumask: introduce new
API, without changing anything") introduced a build breakage on parisc.

This trivial patch fixes it.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kyle Mc Martin <kyle@hera.kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/parisc/include/asm/smp.h

@@ -44,8 +44,6 @@ extern void arch_send_call_function_ipi(cpumask_t mask);
  
 #define PROC_CHANGE_PENALTY	15		/* Schedule penalty */
 
-extern unsigned long cpu_present_mask;
-
 #define raw_smp_processor_id()	(current_thread_info()->cpu)
 
 #else /* CONFIG_SMP */