Fix typos.

Fixes already done in Emacs by Paul Eggert.

lisp/ob-latex.el

@@ -190,7 +190,7 @@ Extracted from `org-export-as-pdf' in org-latex.el."
       pdffile)))
 
 (defun org-babel-prep-session:latex (session params)
-  "Return an error because LaTeX doesn't support sesstions."
+  "Return an error because LaTeX doesn't support sessions."
   (error "LaTeX does not support sessions"))
 
 (provide 'ob-latex)

lisp/org-exp.el

@@ -2333,7 +2333,7 @@ TYPE must be a string, any of:
 			    (plist-get org-export-opt-plist
 				       (intern (concat ":" key)))))
 	  (save-match-data
-	    ;; If arguments are provided, first retreive them properly
+	    ;; If arguments are provided, first retrieve them properly
 	    ;; (in ARGS, as a list), then replace them in VAL.
 	    (when args
 	      (setq args (org-split-string args ",") args2 nil)