convert most variable swaps to mem swaps

src/pdf417/decoder/ec/error_correction.rs

@@ -124,9 +124,7 @@ fn runEuclideanAlgorithm(
     let mut a = a;
     let mut b = b;
     if a.getDegree() < b.getDegree() {
-        let temp = a;
-        a = b;
-        b = temp;
+        std::mem::swap(&mut a,&mut b);
     }
 
     let mut rLast = a;

src/pdf417/decoder/ec/modulus_poly.rs

@@ -139,9 +139,7 @@ impl ModulusPoly {
         let mut smallerCoefficients = &self.coefficients;
         let mut largerCoefficients = &other.coefficients;
         if smallerCoefficients.len() > largerCoefficients.len() {
-            let temp = smallerCoefficients;
-            smallerCoefficients = largerCoefficients;
-            largerCoefficients = temp;
+            std::mem::swap(&mut smallerCoefficients, &mut largerCoefficients);
         }
         let mut sumDiff = vec![0032; largerCoefficients.len()];
         let lengthDiff = largerCoefficients.len() - smallerCoefficients.len();