ob: Fix org-babel-edit-distance for insertion/deletion

* lisp/ob.el (org-babel-edit-distance): When insertion or deletion are
  needed, make sure the distance is incremented.  In addition, the now
  obsolete mmin function was removed.

lisp/ob.el

@@ -629,16 +629,19 @@ arguments and pop open the results in a preview buffer."
 	 (l2 (length s2))
 	 (dist (vconcat (mapcar (lambda (_) (make-vector (1+ l2) nil))
 				(number-sequence 1 (1+ l1)))))
-	 (in (lambda (i j) (aref (aref dist i) j)))
-	 (mmin (lambda (&rest lst) (apply #'min (remove nil lst)))))
+	 (in (lambda (i j) (aref (aref dist i) j))))
     (setf (aref (aref dist 0) 0) 0)
+    (dolist (j (number-sequence 1 l2))
+      (setf (aref (aref dist 0) j) j))
     (dolist (i (number-sequence 1 l1))
+      (setf (aref (aref dist i) 0) i)
       (dolist (j (number-sequence 1 l2))
 	(setf (aref (aref dist i) j)
-	      (+ (if (equal (aref s1 (1- i)) (aref s2 (1- j))) 0 1)
-		 (funcall mmin (funcall in (1- i) j)
-			  (funcall in i (1- j))
-			  (funcall in (1- i) (1- j)))))))
+	      (min
+	       (1+ (funcall in (1- i) j))
+	       (1+ (funcall in i (1- j)))
+	       (+ (if (equal (aref s1 (1- i)) (aref s2 (1- j))) 0 1)
+		  (funcall in (1- i) (1- j)))))))
     (funcall in l1 l2)))
 
 (defun org-babel-combine-header-arg-lists (original &rest others)