xfs: add mssing inode cache attempts counter increment

Increasing the inode cache attempt counter was apparently dropped while
refactoring the cache code and so stayed at the initial 0 value. Add the
increment back to make the runtime stats more useful.
Signed-off-by: NLucas Stach <dev@lynxeye.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

fs/xfs/xfs_icache.c

@@ -412,6 +412,8 @@ xfs_iget(
 	if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount)
 		return -EINVAL;
 
+	XFS_STATS_INC(xs_ig_attempts);
+
 	/* get the perag structure and ensure that it's inode capable */
 	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
 	agino = XFS_INO_TO_AGINO(mp, ino);