[POWERPC] Fix non HUGETLB_PAGE build warning

arch/powerpc/mm/mmu_context_64.c: In function 'init_new_context':
arch/powerpc/mm/mmu_context_64.c:31: warning: unused variable 'new_context'
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/mm/mmu_context_64.c

@@ -28,7 +28,6 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 {
 	int index;
 	int err;
-	int new_context = (mm->context.id == 0);
 
 again:
 	if (!idr_pre_get(&mmu_context_idr, GFP_KERNEL))
@@ -50,19 +49,19 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 		return -ENOMEM;
 	}
 
-	mm->context.id = index;
 #ifdef CONFIG_PPC_MM_SLICES
 	/* The old code would re-promote on fork, we don't do that
 	 * when using slices as it could cause problem promoting slices
 	 * that have been forced down to 4K
 	 */
-	if (new_context)
+	if (mm->context.id == 0)
 		slice_set_user_psize(mm, mmu_virtual_psize);
 #else
 	mm->context.user_psize = mmu_virtual_psize;
 	mm->context.sllp = SLB_VSID_USER |
 		mmu_psize_defs[mmu_virtual_psize].sllp;
 #endif
+	mm->context.id = index;
 
 	return 0;
 }

arch/powerpc/mm/slice.c

@@ -551,6 +551,7 @@ EXPORT_SYMBOL_GPL(get_slice_psize);
  *
  * This is also called in init_new_context() to change back the user
  * psize from whatever the parent context had it set to
+ * N.B. This may be called before mm->context.id has been set.
  *
  * This function will only change the content of the {low,high)_slice_psize
  * masks, it will not flush SLBs as this shall be handled lazily by the