staging: wilc1000: remove set but not used variable 'msa'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/staging/wilc1000/host_interface.c: In function 'wilc_parse_network_info':
drivers/staging/wilc1000/host_interface.c:748:16: warning:
 variable 'msa' set but not used [-Wunused-but-set-variable]

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>