x86/fpu: Make task_xstate_cachep static

It's now local to fpu/core.c, make it static.
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/processor.h

@@ -362,7 +362,6 @@ DECLARE_PER_CPU(struct irq_stack *, softirq_stack);
 #endif	/* X86_64 */
 
 extern unsigned int xstate_size;
-extern struct kmem_cache *task_xstate_cachep;
 
 struct perf_event;
 

arch/x86/kernel/fpu/core.c

@@ -150,8 +150,7 @@ EXPORT_SYMBOL_GPL(fpstate_init);
 /*
  * FPU state allocation:
  */
-struct kmem_cache *task_xstate_cachep;
-EXPORT_SYMBOL_GPL(task_xstate_cachep);
+static struct kmem_cache *task_xstate_cachep;
 
 void fpstate_cache_init(void)
 {