defqueue.hh: eliminate warnings reported by clang-8.0.0

In file included from cslinker.cc:22:
defqueue.hh:58:19: warning: 'const' qualifier on reference type 'TDefByChecker::const_reference' (aka 'const std::pair<const std::__cxx11::basic_string<char>, std::map<std::__cxx11::basic_string<char>, std::__cxx11::list<Defect, std::allocator<Defect> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, std::__cxx11::list<Defect, std::allocator<Defect> > > > > > &') has no effect [-Wignored-qualifiers]
    BOOST_FOREACH(const TDefByChecker::const_reference iRow, stor_)
                  ^~~~~~
/usr/include/boost/foreach.hpp:1107:14: note: expanded from macro 'BOOST_FOREACH'
        for (VAR = BOOST_FOREACH_DEREF(COL); !BOOST_FOREACH_ID(_foreach_continue); BOOST_FOREACH_ID(_foreach_continue) = true)
             ^
In file included from cslinker.cc:22:
defqueue.hh:59:23: warning: 'const' qualifier on reference type 'TDefByFile::const_reference' (aka 'const std::pair<const std::__cxx11::basic_string<char>, std::__cxx11::list<Defect, std::allocator<Defect> > > &') has no effect [-Wignored-qualifiers]
        BOOST_FOREACH(const TDefByFile::const_reference iCol, iRow.second)
                      ^~~~~~
/usr/include/boost/foreach.hpp:1107:14: note: expanded from macro 'BOOST_FOREACH'
        for (VAR = BOOST_FOREACH_DEREF(COL); !BOOST_FOREACH_ID(_foreach_continue); BOOST_FOREACH_ID(_foreach_continue) = true)
             ^
2 warnings generated.

Closes: https://github.com/kdudka/csdiff/pull/10

Author: kdudka

defqueue.hh

@@ -55,8 +55,8 @@ class DefQueue {
 };
 
 template <class TVisitor> bool DefQueue::walk(TVisitor &visitor) {
-    BOOST_FOREACH(const TDefByChecker::const_reference iRow, stor_)
-        BOOST_FOREACH(const TDefByFile::const_reference iCol, iRow.second)
+    BOOST_FOREACH(TDefByChecker::const_reference iRow, stor_)
+        BOOST_FOREACH(TDefByFile::const_reference iCol, iRow.second)
             BOOST_FOREACH(const Defect &def, iCol.second)
                 if (! /* continue */ visitor(def))
                     return false;