remove repetitive words in comments

Signed-off-by: racerole <[email protected]>

core/vm/contracts.go

@@ -1004,7 +1004,7 @@ func (c *bls12381MapG1) RequiredGas(input []byte) uint64 {
 
 func (c *bls12381MapG1) Run(input []byte) ([]byte, error) {
 	// Implements EIP-2537 Map_To_G1 precompile.
-	// > Field-to-curve call expects `64` bytes an an input that is interpreted as a an element of the base field.
+	// > Field-to-curve call expects `64` bytes an input that is interpreted as a an element of the base field.
 	// > Output of this call is `128` bytes and is G1 point following respective encoding rules.
 	if len(input) != 64 {
 		return nil, errBLS12381InvalidInputLength
@@ -1039,7 +1039,7 @@ func (c *bls12381MapG2) RequiredGas(input []byte) uint64 {
 
 func (c *bls12381MapG2) Run(input []byte) ([]byte, error) {
 	// Implements EIP-2537 Map_FP2_TO_G2 precompile logic.
-	// > Field-to-curve call expects `128` bytes an an input that is interpreted as a an element of the quadratic extension field.
+	// > Field-to-curve call expects `128` bytes an input that is interpreted as a an element of the quadratic extension field.
 	// > Output of this call is `256` bytes and is G2 point following respective encoding rules.
 	if len(input) != 128 {
 		return nil, errBLS12381InvalidInputLength