support_kv_pair_splitter: refine code

src/butil/string_splitter.h

@@ -208,7 +208,7 @@ public:
 
     // Get the current value of key and value 
     // in the format of "key=value"
-    inline StringPiece key_and_value(){
+    inline StringPiece key_and_value() {
         return StringPiece(_sp.field(), _sp.length());
     }
 

src/butil/string_splitter_inl.h

@@ -317,7 +317,7 @@ int StringMultiSplitter::to_double(double* pv) const {
 }
 
 void KeyValuePairsSplitter::UpdateDelimiterPosition() {
-    StringPiece key_value_pair(_sp.field(), _sp.length());
+    const StringPiece key_value_pair(key_and_value());
     _deli_pos = key_value_pair.find(_key_value_delimiter);
     if (_deli_pos == StringPiece::npos) {
         _deli_pos = key_value_pair.length();