MdeModulePkg UiApp: Remove a redundant function and a variable

MdeModulePkg UiApp: Remove a redundant function and a variable

1.After the cleanup at "MdeModulePkg UiApp: Remove redundant functions",
  the function "IsResetReminderFeatureEnable()" and the variable
  "mFeaturerSwitch" become redundant so they have been removed.
2.Therefore, the "IF" expression has also been removed, whose judgment condition
  is "IsResetReminderFeatureEnable()".
https://bugzilla.tianocore.org/show_bug.cgi?id=1062

Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: shenglei <shenglei.zhang@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>