fancontrol: Uplift the --check option

- do not duplicate the load code
 - add description to man page

prog/pwm/fancontrol

@@ -390,15 +390,11 @@ function CheckFiles
 	return $outdated
 }
 
+CHECK_ONLY=false
 if [ "$1" == "--check" ]
 then
-	if [ -f "$2" ]
-	then
-		LoadConfig $2
-	else
-		LoadConfig /etc/fancontrol
-	fi
-	exit 0
+	CHECK_ONLY=true
+	shift
 fi
 
 if [ -f "$1" ]
@@ -408,6 +404,10 @@ else
 	LoadConfig /etc/fancontrol
 fi
 
+if $CHECK_ONLY ; then
+	exit 0
+fi
+
 # Detect path to sensors
 if echo "${AFCPWM[0]}" | grep -E -q '^/'
 then

prog/pwm/fancontrol.8

@@ -3,14 +3,22 @@
 fancontrol \- automated software based fan speed regulation
 
 .SH SYNOPSIS
-.B fancontrol
-.I [configfile]
+.B fancontrol [
+.I --check
+.B ] [
+.I configfile
+.B ]
 
 .SH DESCRIPTION
 \fBfancontrol\fP is a shell script for use with lm_sensors. It reads its
 configuration from a file, then calculates fan speeds from temperatures and
 sets the corresponding PWM outputs to the computed values.
 
+.SH OPTIONS
+.IP "--check"
+Check configuration file end exit. This option can be used for verifying the
+configuration before starting fancontrol as a service in the background.
+
 .SH WARNING
 Please be careful when using the fan control features of your mainboard, in
 addition to the risk of burning your CPU, at higher temperatures there will be