Use C++11 std::map::erase return value (#2236)

src/cache.cpp

@@ -546,7 +546,7 @@ bool StatCache::TruncateCache()
             stat_cache_entry* entry = iter->second;
             if(!entry || (0L == entry->notruncate && IsExpireStatCacheTime(entry->cache_date, ExpireTime))){
                 delete entry;
-                stat_cache.erase(iter++);
+                iter = stat_cache.erase(iter);
             }else{
                 ++iter;
             }
@@ -718,7 +718,7 @@ bool StatCache::TruncateSymlink()
             symlink_cache_entry* entry = iter->second;
             if(!entry || IsExpireStatCacheTime(entry->cache_date, ExpireTime)){  // use the same as Stats
                 delete entry;
-                symlink_cache.erase(iter++);
+                iter = symlink_cache.erase(iter);
             }else{
                 ++iter;
             }

src/fdcache.cpp

@@ -730,12 +730,12 @@ bool FdManager::Close(FdEntity* ent, int fd)
             ent->Close(fd);
             if(!ent->IsOpen()){
                 // remove found entity from map.
-                fent.erase(iter++);
+                iter = fent.erase(iter);
 
                 // check another key name for entity value to be on the safe side
                 for(; iter != fent.end(); ){
                     if(iter->second == ent){
-                        fent.erase(iter++);
+                        iter = fent.erase(iter);
                     }else{
                         ++iter;
                     }
@@ -754,7 +754,7 @@ bool FdManager::ChangeEntityToTempPath(FdEntity* ent, const char* path)
 
     for(fdent_map_t::iterator iter = fent.begin(); iter != fent.end(); ){
         if(iter->second == ent){
-            fent.erase(iter++);
+            iter = fent.erase(iter);
 
             std::string tmppath;
             FdManager::MakeRandomTempPath(path, tmppath);

src/fdcache_entity.cpp

@@ -2378,7 +2378,7 @@ bool FdEntity::MergeOrgMeta(headers_t& updatemeta)
     // this is special cases, we remove the key which has empty values.
     for(headers_t::iterator hiter = orgmeta.begin(); hiter != orgmeta.end(); ){
         if(hiter->second.empty()){
-            orgmeta.erase(hiter++);
+            hiter = orgmeta.erase(hiter);
         }else{
             ++hiter;
         }