SecurityPkg/Tpm12CommandLib: Always check response returnCode
    
    https://bugzilla.tianocore.org/show_bug.cgi?id=338
    
    Update the Tpm12CommandLib to consistently check the returnCode
    field of a response packet.  These checks are missing from the
    GetCapability and SelfTest commands.  The functions
    Tpm12ContinueSelfTest(), Tpm12GetCapabilityFlagPermanent(), and
    Tpm12GetCapabilityFlagVolatile() are updated to verify that the
    response returnCode is not an error.
    
    Cc: Chao Zhang <chao.b.zhang@intel.com>
    Cc: Jiewen Yao <jiewen.yao@intel.com>
    Contributed-under: TianoCore Contribution Agreement 1.0
    Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
    Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
    Reviewed-by: Chao Zhang <chao.b.zhang@intel.com>