org-element: Fix inline-src-block parsing at the beginning of an item

* lisp/org-element.el (org-element-inline-src-block-successor): Fix
  inline-src-block parsing at the beginning of an item.
* testing/lisp/test-org-element.el: Add test.

lisp/org-element.el

@@ -2612,6 +2612,7 @@ LIMIT bounds the search.
 Return value is a cons cell whose CAR is `inline-babel-call' and
 CDR is beginning position."
   (save-excursion
+    (unless (bolp) (backward-char))
     (when (re-search-forward org-babel-inline-src-block-regexp limit t)
       (cons 'inline-src-block (match-beginning 1)))))
 

testing/lisp/test-org-element.el

@@ -825,6 +825,10 @@ CLOCK: [2012-01-01 sun. 00:01]--[2012-01-01 sun. 00:02] =>  0:01"
   "Test `inline-src-block' parser."
   (should
    (org-test-with-temp-text "src_emacs-lisp{(+ 1 1)}"
+     (org-element-map (org-element-parse-buffer) 'inline-src-block 'identity)))
+  ;; Test parsing at the beginning of an item.
+  (should
+   (org-test-with-temp-text "- src_emacs-lisp{(+ 1 1)}"
      (org-element-map (org-element-parse-buffer) 'inline-src-block 'identity))))