minor bug fix to resolve compatiblity issue

	modified:   splicesitemap.cpp

splicesitemap.cpp

@@ -138,7 +138,7 @@ static void sort_splice_sites (splice_site_t ** ss, int n_ss)
 
 struct cmp_str
 {
-   bool operator()(char const *a, char const *b) {
+   bool operator()(char const *a, char const *b) const {
       return strcmp(a, b) < 0;
    }
 };