fix script output filename

main/cert/gen_attestation_devive_cert.sh

@@ -3,7 +3,7 @@ set -e
 openssl ecparam -out ec_key.pem -name secp256r1 -genkey -out dev.key
 openssl req -config ./attestation-device-cert.cnf -new -key dev.key -nodes -out dev.csr
 openssl x509 -extfile ./attestation-device-cert.cnf -extensions extensions_sec -days 3560 -req -in dev.csr -CA ca.pem -CAserial ca.srl -CAkey ca.key -out dev.pem
-openssl x509 -outform der -in dev.pem -out dev.der
+openssl x509 -outform der -in dev.pem -out u2f_cert.bin
 rm dev.csr
 
 openssl ec -in dev.key -outform DER -no_public | tail -c +8 | head -c 32  > u2f_cert_key.bin