staging: rtl8192u: Deleted 'HTUseDefaultSetting' function in ieee80211/rtl819x_HTProc.c

This patch delete the 'HTUseDefaultSetting' function that is not used in anywhere in the driver.

Fix the following sparse warnings in ieee80211/rtl819x_HTProc.c

drivers/staging/rtl8192u/ieee80211/rtl819x_HTProc.c:1323:6: warning: symbol 'HTUseDefaultSetting' was not declared. Should it be static?

Signed-off-by: Ana Rey <anarey@gmail.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>