SecurityPkg/Tcg: Fix typos in TcgDxe.c and Tcg2Dxe.c

SecurityPkg/Tcg: Fix typos in TcgDxe.c and Tcg2Dxe.c

Change EFI_RETURNING_FROM_EFI_APPLICATOIN to
EFI_RETURNING_FROM_EFI_APPLICATION.
https://bugzilla.tianocore.org/show_bug.cgi?id=1368

Cc: Chao Zhang <chao.b.zhang@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Chao Zhang <chao.b.zhang@intel.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>