Review comments: config variable, inverted file check

Author: tdewey-rpi

host-support/config

@@ -1,4 +1,5 @@
 CUSTOMER_KEY_FILE_PEM=
+CUSTOMER_KEY_PKCS11_NAME=
 GOLD_MASTER_OS_FILE=
 RPI_DEVICE_STORAGE_TYPE=
 RPI_DEVICE_FAMILY=

host-support/terminal-functions.sh

@@ -137,7 +137,7 @@ get_signing_directives() {
         echo "${CUSTOMER_KEY_PKCS11_NAME} -engine pkcs11 -keyform engine"
     else
         if [ -n "${CUSTOMER_KEY_FILE_PEM}" ]; then
-            if [ -f "${CUSTOMER_KEY_FILE_PEM}" ]; then
+            if [ ! -f "${CUSTOMER_KEY_FILE_PEM}" ]; then
                 echo "RSA private key \"${CUSTOMER_KEY_FILE_PEM}\" not a file. Aborting." >&2
                 exit 1
             fi