[POWERPC] Remove duplicate variable definitions in mm/tlb_64.c

Somewhere along the way (e28f7faf05159f1cfd564596f5e6178edba6bd49,
"Four level pagetables for ppc64") we ended up with duplicate
definitions for pte_freelist_cur and pte_freelist_force_free.
Somehow this compiles, but it would be better to just have one
definition for each.

The two definitions we end up with can be static too!

Signed-off-by: Michael Ellerman <[e-mail]>
Signed-off-by: Paul Mackerras <[e-mail]>

arch/powerpc/mm/tlb_64.c

···
  * include/asm-powerpc/tlb.h file -- tgall
  */
 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
-unsigned long pte_freelist_forced_free;
+static DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
+static unsigned long pte_freelist_forced_free;
 
 struct pte_freelist_batch
 {
···
 	unsigned int	index;
 	pgtable_free_t	tables[0];
 };
-
-DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
-unsigned long pte_freelist_forced_free;
 
 #define PTE_FREELIST_SIZE \
 	((PAGE_SIZE - sizeof(struct pte_freelist_batch)) \