org-entities: Fix "infin" entity

* lisp/org-entities.el (org-entities): Fix infin entity in LaTeX.

Suggested-by: Leandro Facchinetti <me@leafac.com>

lisp/org-entities.el

@@ -326,7 +326,7 @@ packages to be loaded, add these packages to `org-latex-packages-alist'."
      ("deg" "\\textdegree{}" nil "°" "degree" "°" "°")
      ("prime" "\\prime" t "′" "'" "'" "′")
      ("Prime" "\\prime{}\\prime" t "″" "''" "''" "″")
-     ("infin" "\\propto" t "∞" "[infinity]" "[infinity]" "∞")
+     ("infin" "\\infty" t "∞" "[infinity]" "[infinity]" "∞")
      ("infty" "\\infty" t "∞" "[infinity]" "[infinity]" "∞")
      ("prop" "\\propto" t "∝" "[proportional to]" "[proportional to]" "∝")
      ("propto" "\\propto" t "∝" "[proportional to]" "[proportional to]" "∝")