Do not request use of urandom and report failure

Original script did not report failure as exit status. Report error if
rndc key generation failed also by exit status, not only by failed
message.

-r parameter is unsupported now, do not require it anymore.

generate-rndc-key.sh

@@ -6,7 +6,7 @@
 
 if [ ! -s /etc/rndc.key -a ! -s /etc/rndc.conf ]; then
   echo -n $"Generating /etc/rndc.key:"
-  if /usr/sbin/rndc-confgen -a -A hmac-sha256 -r /dev/urandom > /dev/null 2>&1
+  if /usr/sbin/rndc-confgen -a -A hmac-sha256 > /dev/null 2>&1
   then
     chmod 640 /etc/rndc.key
     chown root:named /etc/rndc.key
@@ -16,5 +16,6 @@ if [ ! -s /etc/rndc.key -a ! -s /etc/rndc.conf ]; then
   else
     failure $"/etc/rndc.key generation"
     echo
+    exit 1
   fi
 fi