wireless: Fix warnings due to -Wunused-but-set-variable

These warnings are exposed by gcc 4.6.
net/wireless/reg.c: In function 'freq_reg_info_regd':
net/wireless/reg.c:675:38: warning: variable 'pr' set but not used
[-Wunused-but-set-variable]
net/wireless/lib80211_crypt_wep.c: In function 'lib80211_wep_build_iv':
net/wireless/lib80211_crypt_wep.c:99:12: warning: variable 'len' set but
not used [-Wunused-but-set-variable]

Signed-off-by: Rajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>