Update Jenkinsfile - fixing linting error in Jenkinsfile (#3891)

Author: blue-jaye-121

benchmarks/Jenkinsfile

@@ -63,7 +63,7 @@ pipeline {
         // Pushes to the git repo if there have been changes
 		stage('Update results repo') {
 			steps {
-				withCredentials([sshUserPrivateKey(credentialsId: 'GH_DEPLOY_KEY_METPY_BENCH_RESULTS', keyFileVariable: 'deploy_key')]) { {
+				withCredentials([sshUserPrivateKey(credentialsId: 'GH_DEPLOY_KEY_METPY_BENCH_RESULTS', keyFileVariable: 'deploy_key')]) {
                     sh '''
 				   	if [ -n "$(git status --porcelain)" ]; then 
 						cd ${CLONE_DIR}