fix cupyx.scipy.get_array_module's docstring
It says that the function returns cupy module, but in fact it returns
cupyx.scipy module.
@@ -18,7 +18,7 @@ def get_array_module(*args):
"""Returns the array module for arguments.
This function is used to implement CPU/GPU generic code. If at least one of
- the arguments is a :class:`cupy.ndarray` object, the :mod:`cupy` module is
+ the arguments is a :class:`cupy.ndarray` object, the :mod:`cupyx.scipy` module is
returned.
Args:
