xfs: get mp from bma->ip in xfs_bmap code

In my earlier commit

  c29aad41 xfs: pass mp to XFS_WANT_CORRUPTED_GOTO

I added some local mp variables with code which indicates that
mp might be NULL.  Coverity doesn't like this now, because the
updated per-fs XFS_STATS macros dereference mp.

I don't think this is actually a problem; from what I can tell,
we cannot get to these functions with a null bma->tp, so my NULL
check was probably pointless.  Still, it's not super obvious.

So switch this code to get mp from the inode on the xfs_bmalloca
structure, with no conditional, because the functions are already
using bmap->ip directly.

Addresses-Coverity-Id: 1339552
Addresses-Coverity-Id: 1339553
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/libxfs/xfs_bmap.c

@@ -1725,7 +1725,7 @@ xfs_bmap_add_extent_delay_real(
 	int			tmp_rval;	/* partial logging flags */
 	struct xfs_mount	*mp;
 
-	mp  = bma->tp ? bma->tp->t_mountp : NULL;
+	mp = bma->ip->i_mount;
 	ifp = XFS_IFORK_PTR(bma->ip, XFS_DATA_FORK);
 
 	ASSERT(bma->idx >= 0);
@@ -2939,7 +2939,7 @@ xfs_bmap_add_extent_hole_real(
 	int			state;	/* state bits, accessed thru macros */
 	struct xfs_mount	*mp;
 
-	mp = bma->tp ? bma->tp->t_mountp : NULL;
+	mp = bma->ip->i_mount;
 	ifp = XFS_IFORK_PTR(bma->ip, whichfork);
 
 	ASSERT(bma->idx >= 0);