staging: wfx: remove spaces after cast operator

The kernel coding style expects no space after cast operator. This patch
make the wfx driver compliant with this rule.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200505123757.39506-15-Jerome.Pouiller@silabs.com


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