fs/zfs: Fix another memory leak in ZFS code

Commit b66c6f918 (fs/zfs: Fix a number of memory leaks in ZFS code)
fixes many of the same leaks detected in bug #63846 except one, which
is fixed here.

Fixes: https://savannah.gnu.org/bugs/?63846
Fixes: b66c6f918 (fs/zfs: Fix a number of memory leaks in ZFS code)

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

grub-core/fs/zfs/zfs.c

@@ -3052,6 +3052,7 @@ dnode_get_path (struct subvolume *subvol, const char *path_in, dnode_end_t *dn,
 	  void *sahdrp;
 	  int hdrsize;
 	  grub_size_t sz;
+	  bool free_sahdrp = false;
 
 	  if (dnode_path->dn.dn.dn_bonuslen != 0)
 	    {
@@ -3064,6 +3065,7 @@ dnode_get_path (struct subvolume *subvol, const char *path_in, dnode_end_t *dn,
 	      err = zio_read (bp, dnode_path->dn.endian, &sahdrp, NULL, data);
 	      if (err)
 	        break;
+	      free_sahdrp = true;
 	    }
 	  else
 	    {
@@ -3122,6 +3124,9 @@ dnode_get_path (struct subvolume *subvol, const char *path_in, dnode_end_t *dn,
 		     }
 	      dn_new = dnode_path;
 	    }
+	  if (free_sahdrp == true)
+	    grub_free (sahdrp);
+
 	}
     }