powerpc: Make slb_shadow a local

The only external user of slb_shadow is the pseries lpar code, and it
can access through the paca array instead.

Signed-off-by: Jeremy Kerr <[e-mail]>
Signed-off-by: Benjamin Herrenschmidt <[e-mail]>

arch/powerpc/include/asm/lppaca.h

···
 	} save_area[SLB_NUM_BOLTED];
 } ____cacheline_aligned;
 
-extern struct slb_shadow slb_shadow[];
-
 /*
  * Layout of entries in the hypervisor's dispatch trace log buffer.
  */

arch/powerpc/kernel/paca.c

···
  * 3 persistent SLBs are registered here.  The buffer will be zero
  * initially, hence will all be invaild until we actually write them.
  */
-struct slb_shadow slb_shadow[] __cacheline_aligned = {
+static struct slb_shadow slb_shadow[] __cacheline_aligned = {
 	[0 ... (NR_CPUS-1)] = {
 		.persistent = cpu_to_be32(SLB_NUM_BOLTED),
 		.buffer_length = cpu_to_be32(sizeof(struct slb_shadow)),

arch/powerpc/platforms/pseries/lpar.c

···
 	 * PAPR says this feature is SLB-Buffer but firmware never
 	 * reports that.  All SPLPAR support SLB shadow buffer.
 	 */
-	addr = __pa(&slb_shadow[cpu]);
+	addr = __pa(paca[cpu].slb_shadow_ptr);
 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
 		ret = register_slb_shadow(hwcpu, addr);
 		if (ret)