using neater writeEntryIfDifferent syntax

src/finiteVolume/fields/fvPatchFields/derived/buoyantPressure/buoyantPressureFvPatchScalarField.C

@@ -136,7 +136,7 @@ void buoyantPressureFvPatchScalarField::updateCoeffs()
 void buoyantPressureFvPatchScalarField::write(Ostream& os) const
 {
     fixedGradientFvPatchScalarField::write(os);
-    os.writeKeyword("rho") << rhoName_ << token::END_STATEMENT << nl;
+    writeEntryIfDifferent<word>(os, "rho", "rho", rhoName_);
     writeEntry("value", os);
 }
 

src/finiteVolume/fields/fvPatchFields/derived/flowRateInletVelocity/flowRateInletVelocityFvPatchVectorField.C

@@ -159,14 +159,8 @@ void Foam::flowRateInletVelocityFvPatchVectorField::write(Ostream& os) const
 {
     fvPatchField<vector>::write(os);
     os.writeKeyword("flowRate") << flowRate_ << token::END_STATEMENT << nl;
-    if (phiName_ != "phi")
-    {
-        os.writeKeyword("phi") << phiName_ << token::END_STATEMENT << nl;
-    }
-    if (rhoName_ != "rho")
-    {
-        os.writeKeyword("rho") << rhoName_ << token::END_STATEMENT << nl;
-    }
+    writeEntryIfDifferent<word>(os, "phi", "phi", phiName_);
+    writeEntryIfDifferent<word>(os, "rho", "rho", rhoName_);
     writeEntry("value", os);
 }