remove save-excursion inside save-window-excursion

it is not necessary

* lisp/ob-R.el (org-babel-R-initiate-session): Remove unnecessary
  save-excursion nested inside a save-window-excursion.

lisp/ob-R.el

@@ -209,18 +209,17 @@ This function is called by `org-babel-execute-src-block'."
       (if (org-babel-comint-buffer-livep session)
 	  session
 	(save-window-excursion
-	  (save-excursion
-	    (when (get-buffer session)
-	      ;; Session buffer exists, but with dead process
-	      (set-buffer session))
-	    (require 'ess) (R)
-	    (rename-buffer
-	     (if (bufferp session)
-		 (buffer-name session)
-	       (if (stringp session)
-		   session
-		 (buffer-name))))
-	    (current-buffer)))))))
+	  (when (get-buffer session)
+	    ;; Session buffer exists, but with dead process
+	    (set-buffer session))
+	  (require 'ess) (R)
+	  (rename-buffer
+	   (if (bufferp session)
+	       (buffer-name session)
+	     (if (stringp session)
+		 session
+	       (buffer-name))))
+	  (current-buffer))))))
 
 (defun org-babel-R-associate-session (session)
   "Associate R code buffer with an R session.