xfs: fix the zoned RT growfs check for zone alignment

The grofs code for zoned RT subvolums already tries to check for zone
alignment, but gets it wrong by using the old instead of the new mount
structure.

Fixes: 01b71e6 ("xfs: support growfs on zoned file systems")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: stable@vger.kernel.org # v6.15
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Author: Christoph Hellwig

fs/xfs/xfs_rtalloc.c

@@ -1255,29 +1255,31 @@ xfs_growfs_check_rtgeom(
 	min_logfsbs = min_t(xfs_extlen_t, xfs_log_calc_minimum_size(nmp),
 			nmp->m_rsumblocks * 2);
 
-	kfree(nmp);
-
 	trace_xfs_growfs_check_rtgeom(mp, min_logfsbs);
 
 	if (min_logfsbs > mp->m_sb.sb_logblocks)
-		return -EINVAL;
+		goto out_inval;
 
 	if (xfs_has_zoned(mp)) {
 		uint32_t	gblocks = mp->m_groups[XG_TYPE_RTG].blocks;
 		uint32_t	rem;
 
 		if (rextsize != 1)
 			return -EINVAL;
-		div_u64_rem(mp->m_sb.sb_rblocks, gblocks, &rem);
+		div_u64_rem(nmp->m_sb.sb_rblocks, gblocks, &rem);
 		if (rem) {
 			xfs_warn(mp,
 "new RT volume size (%lld) not aligned to RT group size (%d)",
-				mp->m_sb.sb_rblocks, gblocks);
-			return -EINVAL;
+				nmp->m_sb.sb_rblocks, gblocks);
+			goto out_inval;
 		}
 	}
 
+	kfree(nmp);
 	return 0;
+out_inval:
+	kfree(nmp);
+	return -EINVAL;
 }
 
 /*