staging: r8712u: Update TODO for sparse fixes

Signed-off-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/rtl8712/TODO

@@ -3,7 +3,6 @@ TODO:
 - switch to use LIB80211
 - switch to use MAC80211
 - checkpatch.pl fixes - only a few remain
-- sparse fixes
 - switch from large inline firmware file to use the firmware interface
   and add the file to the linux-firmware package.