LU-14600 e2fsck: trusted.link unref inode test case

LU-14600 e2fsck: trusted.link unref inode test case

Update the f_trusted_link test case to include a locally
unreferenced inode that has a trusted.link xattr.  The
inode should be linked into lost+found because of the xattr,
even if it has no blocks/data, and the link cound should be
extracted from the trusted.link xattr.

Change-Id: Ifad410d0bc1ceb140216dbed48e54ea3825abe3b
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/43335
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Li Dongyang <dongyangli@ddn.com>
Tested-by: Maloo <maloo@whamcloud.com>