staging: r8188eu: change void parameters to u8

staging: r8188eu: change void parameters to u8

The second parameter of write_fw(), page_write() and block_write()
is a void pointer, but we always pass an u8 pointer. We can convert
this parameter to an u8 pointer. The pointer is not changed in the
functions, so we can safely remove the local variable bufferPtr.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220412185754.8695-4-straube.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>