[2.7] bpo-31754: Fix type of 'itemsize' in PyBuffer_FillContiguousStrides (GH-3993)

diff --git a/Doc/c-api/buffer.rst b/Doc/c-api/buffer.rst
index 050db55..4e5a043 100644
--- a/Doc/c-api/buffer.rst
+++ b/Doc/c-api/buffer.rst
@@ -278,7 +278,7 @@
    (*fortran* is ``'A'``).  Return ``0`` otherwise.
 
 
-.. c:function:: void PyBuffer_FillContiguousStrides(int ndim, Py_ssize_t *shape, Py_ssize_t *strides, Py_ssize_t itemsize, char fortran)
+.. c:function:: void PyBuffer_FillContiguousStrides(int ndims, Py_ssize_t *shape, Py_ssize_t *strides, int itemsize, char fortran)
 
    Fill the *strides* array with byte-strides of a contiguous (C-style if
    *fortran* is ``'C'`` or Fortran-style if *fortran* is ``'F'``) array of the