MdeModulePkg/SmmCore: SMM register protocol notify function clarify
MdeModulePkg/SmmCore: SMM register protocol notify function clarify

PI 1.4 clarified SMM register protocol notify function return status as below:
EFI_SUCCESS           Successfully returned the registration record that has
                      been added or unhooked
EFI_INVALID_PARAMETER Protocol is NULL or Registration is NULL
The implementation of SmmRegisterProtocolNotify() already followed this new
rule, needn't to be updated.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

git-svn-id: 3158a46dfd52e07d1fda3e32e1ab2e353a00b20f@17349 6f19259b-4bc3-4df7-8a09-765794883524

MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2