The wl1251 driver was generating the following warning:
drivers/net/wireless/wl1251/boot.c:467:21: warning: incorrect type in assignment (different base types)
drivers/net/wireless/wl1251/boot.c:467:21: expected unsigned int [unsigned] [assigned] [usertype] val
drivers/net/wireless/wl1251/boot.c:467:21: got restricted __le32 [usertype] <noident>
Fix this by removing one cpu_to_le32() call in the wrong place.