ENH: simplify primitiveEntry parsing code, move append new tokens

- simplify string output code

src/OpenFOAM/db/dictionary/functionEntries/functionEntry/functionEntry.C

@@ -160,13 +160,16 @@ bool Foam::functionEntry::execute
 void Foam::functionEntry::write(Ostream& os) const
 {
     // Contents should be single string token
-    const token& t = operator[](0);
-    const string& s = t.stringToken();
+    const token& tok = operator[](0);
+    const string& s = tok.stringToken();
 
-    for (size_t i = 0; i < s.size(); i++)
+    // Write character-wise for literal output
+    for (size_t i = 0; i < s.size(); ++i)
     {
         os.write(s[i]);
     }
+
+    os << nl;
 }