Add checks for nothing before or nothing after the pipe and output an error when pipe usage fails.
signed-off-by: jcarsey
reviewed-by: leegrosenbaum
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12903 6f19259b-4bc3-4df7-8a09-765794883524