xfs: Test infinite loop while searching for a free inode slot

xfs: Test infinite loop while searching for a free inode slot

Tests the search algorithm for a free inode slot in a specific AG,
done in xfs_dialloc_ag_inobt().

When finobt is not used, and agi->freecount is not 0, XFS will scan
the AG inode tree looking for a free inode slot, but if
agi->freecount is corrupted, and there is no free slot at all, it
will end up in an infinite loop.

This test checks for the infinite loop fix.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>