staging: wfx: fix access to le32 attribute 'ps_mode_error'

The attribute ps_mode_error is little-endian. We have to take to the
endianness when we access it.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200512150414.267198-9-Jerome.Pouiller@silabs.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>