staging: wfx: uniformize naming rule

In wfx driver, when a function is used as a struct member, its name is
the name of the member prefixed with "wfx_".

This patch apply this rule to wfx_spi_remove().

Also remove the useless comment above the function.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20191217161318.31402-17-Jerome.Pouiller@silabs.com


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