cql: fix pessimizing moves

Remove pessimizing moves, as reported by gcc 9.

cql3/functions/functions.cc

@@ -194,7 +194,7 @@ make_from_json_function(database& db, const sstring& keyspace, data_type t) {
         if (!json_value.isNull()) {
             parsed_json_value.emplace(t->from_json_object(json_value, sf));
         }
-        return std::move(parsed_json_value);
+        return parsed_json_value;
     });
 }
 

cql3/restrictions/single_column_primary_key_restrictions.hh

@@ -288,7 +288,7 @@ private:
                     if (def->type->is_reversed()) {
                         ranges.back().reverse();
                     }
-                    return std::move(ranges);
+                    return ranges;
                 }
 
                 ranges.reserve(cartesian_product_size(vec_of_values));
@@ -317,7 +317,7 @@ private:
                     }
                 }
 
-                return std::move(ranges);
+                return ranges;
             }
 
             auto values = r->values(options);
@@ -337,7 +337,7 @@ private:
             ranges.emplace_back(range_type::make_singular(ValueType::from_optional_exploded(*_schema, std::move(prefix))));
         }
 
-        return std::move(ranges);
+        return ranges;
     }
 
 public: