staging: wilc1000: remove unnecessary bracket used in switch in wilc_mgmt_frame_register()

Cleanup patch to remove the curly braces used in 'case' statement to follow as
per linux standard.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>