mm: mmap: fix documentation for vma_mas_szero

When the struct_mm input, mm, was changed to a struct ma_state, mas, the
documentation for the function was never updated.  This updates that
documentation reference.

Link: https://lkml.kernel.org/r/20221114003349.41235-1-ian@linux.cowan.aeroSigned-off-by: NIan Cowan <ian@linux.cowan.aero>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

mm/mmap.c

@@ -456,7 +456,7 @@ void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas)
  * vma_mas_szero() - Set a given range to zero.  Used when modifying a
  * vm_area_struct start or end.
  *
- * @mm: The struct_mm
+ * @mas: The maple tree ma_state
  * @start: The start address to zero
  * @end: The end address to zero.
  */