fix(batch): fix regression introduced by acf12a6

In batch mode, $echo_cmd was not initialized early
enough, and caused this error:
./spectre-meltdown-checker.sh: 899: ./spectre-meltdown-checker.sh: -ne: not found
Fix it by initing echo_cmd unconditionally at the start

spectre-meltdown-checker.sh

@@ -99,14 +99,6 @@ global_critical=0
 global_unknown=0
 nrpe_vuln=""
 
-echo_cmd=''
-__echo()
-{
-	opt="$1"
-	shift
-	_msg="$@"
-
-	if [ -z "$echo_cmd" ]; then
 # find a sane `echo` command
 # we'll try to avoid using shell builtins that might not take options
 if which echo >/dev/null 2>&1; then
@@ -117,7 +109,11 @@ __echo()
 fi
 # still empty ? fallback to builtin
 [ -z "$echo_cmd" ] && echo_cmd=echo
-	fi
+__echo()
+{
+	opt="$1"
+	shift
+	_msg="$@"
 
 	if [ "$opt_no_color" = 1 ] ; then
 		# strip ANSI color codes