sync patch r11825 from main trunk.
For BaseLib IsNull() function , update retval value comment to match its function description. 

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/branches/UDK2008@13048 6f19259b-4bc3-4df7-8a09-765794883524
2 files changed