staging: wilc1000: remove EXPORT_SYMTAB

The EXPORT_SYMTAB symbol has not been used in Linux for a very
long time, the driver does not need to set it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>