1) Use the binaries of boot sector directly instead of building it. Because the code of boot sector will be modified rarely and it is native code.
2) Correct the shell binary file path which is changed by recently.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8620 6f19259b-4bc3-4df7-8a09-765794883524