MdeModulePkg: Enhance error handling in NetLibGetMacAddress() of DxeNetLib.

Signed-off-by: xdu2
Reviewed-by: vanjeff

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12572 6f19259b-4bc3-4df7-8a09-765794883524
1 file changed