IntelFrameworkPkg/FrameworkUefiLib: don't special-case EFI_FILE_MODE_CREATE

IntelFrameworkPkg/FrameworkUefiLib: don't special-case EFI_FILE_MODE_CREATE

Synchronize EfiOpenFileByDevicePath() with the MdePkg/UefiLib instance, as
described in the previous patch.

Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Suggested-by: Ruiyu Ni <ruiyu.ni@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1074
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>