span_types/assignments: no * in device list

If there are no dahdi devices, $devbase/* expans to have a literal '*',
which leads to warnings such as:
/usr/sbin/dahdi_span_types: 1: cd: can't cd to /sys/bus/dahdi_devices/devices/*

Let's just avoid those.

Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>

dahdi_span_assignments

@@ -141,7 +141,7 @@ fi
 if [ "$#" -gt 0 ]; then
 	DEVICES="$@"
 else
-	DEVICES=`echo $devbase/*`
+	DEVICES=`ls -d $devbase/* 2>/dev/null`
 fi
 
 # Beware of special characters in attributes

dahdi_span_types

@@ -120,7 +120,7 @@ fi
 if [ "$#" -gt 0 ]; then
 	DEVICES="$@"
 else
-	DEVICES=`echo $devbase/*`
+	DEVICES=`ls -d $devbase/* 2>/dev/null`
 fi
 
 # Beware of special characters in attributes