uprobes: Fold uprobe_reset_state() into uprobe_dup_mmap()

Now that we have uprobe_dup_mmap() we can fold uprobe_reset_state()
into the new hook and remove it. mmput()->uprobe_clear_state() can't
be called before dup_mmap().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 33870b1..610e1c8 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1148,16 +1148,10 @@
 	kfree(area);
 }
 
-/*
- * uprobe_reset_state - Free the area allocated for slots.
- */
-void uprobe_reset_state(struct mm_struct *mm)
-{
-	mm->uprobes_state.xol_area = NULL;
-}
-
 void uprobe_dup_mmap(struct mm_struct *oldmm, struct mm_struct *newmm)
 {
+	newmm->uprobes_state.xol_area = NULL;
+
 	if (test_bit(MMF_HAS_UPROBES, &oldmm->flags))
 		set_bit(MMF_HAS_UPROBES, &newmm->flags);
 }