scsi: csiostor: Fix NULL check before debugfs_remove_recursive

debugfs_remove_recursive() has taken the null pointer into account.  Remove
the null check before debugfs_remove_recursive().

Link: https://lore.kernel.org/r/20191026195625.GA22455@sauravSigned-off-by: Saurav Girepunje <saurav.girepunje@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/csiostor/csio_init.c

@@ -157,8 +157,7 @@ csio_dfs_create(struct csio_hw *hw)
 static int
 csio_dfs_destroy(struct csio_hw *hw)
 {
-	if (hw->debugfs_root)
-		debugfs_remove_recursive(hw->debugfs_root);
+	debugfs_remove_recursive(hw->debugfs_root);
 
 	return 0;
 }