xfs/348: update error message when transmogrifying symlink into directory

xfs/348: update error message when transmogrifying symlink into directory

We introduced the inline directory verifier in 4.11 to prevent the
system from trying to use corrupt inline directories.  This has the
effect of changing the error message in one step of the i_mode fuzz
tester, so update the test accordingly.

Note that prior to the existence of the verifier, this test would
occasionally result in memory corruption that did not become evident
until later.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eryu Guan <eguan@redhat.com>