index: do not sort index before git_vector_bsearch2()

git_vector_bsearch2() calls git_vector_sort(). No need to call it
directly.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

src/index.c

@@ -494,7 +494,6 @@ int git_index_remove(git_index *index, int position)
 
 int git_index_find(git_index *index, const char *path)
 {
-	sort_index(index);
 	return git_vector_bsearch2(&index->entries, index_srch, path);
 }