GenFds Tool: Fix the bug that the GUID section can't content more than one leaf section.
GenFds Tool: Fix the bug that the GUID section can't content more than one leaf section.

git-svn-id: 5648d1bec6962b0a6d1d1b40eba8cf5cdb62da3d@3620 6f19259b-4bc3-4df7-8a09-765794883524

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