NFSv4.1/pnfs: Fixup an lo->plh_block_lgets imbalance in layoutreturn

Since commit 2d8ae84fbc32, nothing is bumping lo->plh_block_lgets in the
layoutreturn path, so it should not be touched in nfs4_layoutreturn_release
either.

Fixes: 2d8ae84fbc32 ("NFSv4.1/pnfs: Remove redundant lo->plh_block_lgets...")
Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4proc.c

@@ -8057,7 +8057,6 @@ static void nfs4_layoutreturn_release(void *calldata)
 		pnfs_set_layout_stateid(lo, &lrp->res.stateid, true);
 	pnfs_mark_matching_lsegs_invalid(lo, &freeme, &lrp->args.range);
 	pnfs_clear_layoutreturn_waitbit(lo);
-	lo->plh_block_lgets--;
 	spin_unlock(&lo->plh_inode->i_lock);
 	pnfs_free_lseg_list(&freeme);
 	pnfs_put_layout_hdr(lrp->args.layout);