xfs: create a xchk_trans_alloc_empty helper for scrub

Create a helper to initialize empty transactions on behalf of a scrub
operation.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/scrub/common.c

@@ -653,6 +653,13 @@ xchk_trans_cancel(
 	sc->tp = NULL;
 }
 
+int
+xchk_trans_alloc_empty(
+	struct xfs_scrub	*sc)
+{
+	return xfs_trans_alloc_empty(sc->mp, &sc->tp);
+}
+
 /*
  * Grab an empty transaction so that we can re-grab locked buffers if
  * one of our btrees turns out to be cyclic.
@@ -672,7 +679,7 @@ xchk_trans_alloc(
 		return xfs_trans_alloc(sc->mp, &M_RES(sc->mp)->tr_itruncate,
 				resblks, 0, 0, &sc->tp);
 
-	return xfs_trans_alloc_empty(sc->mp, &sc->tp);
+	return xchk_trans_alloc_empty(sc);
 }
 
 /* Set us up with a transaction and an empty context. */

fs/xfs/scrub/common.h

@@ -32,6 +32,7 @@ xchk_should_terminate(
 }
 
 int xchk_trans_alloc(struct xfs_scrub *sc, uint resblks);
+int xchk_trans_alloc_empty(struct xfs_scrub *sc);
 void xchk_trans_cancel(struct xfs_scrub *sc);
 
 bool xchk_process_error(struct xfs_scrub *sc, xfs_agnumber_t agno,

fs/xfs/scrub/fscounters.c

@@ -242,7 +242,7 @@ xchk_setup_fscounters(
 			return error;
 	}
 
-	return xfs_trans_alloc_empty(sc->mp, &sc->tp);
+	return xchk_trans_alloc_empty(sc);
 }
 
 /*