hotplug: Do not run auto span configuration if spans are auto assigned.

This reapplies the change made in commit (6ed0adc08 "dahdi_span_config: Do not run auto
span configuration if spans are auto assigned.") which appears to have been
accidentally removed in (7f826a7d35 "hotplug modularization: split logic to
scriptlets").

To rationale from commit 6ed0adc08:

I have seen cases were users run:

  # modprobe <driver>; dahdi_cfg -c <custom config file>

and the spans end up misconfigured because dahdi_span_assignments ends up
running, via udev, after the user configured the span the way it wanted.

dahdi_span_assignments now looks at auto_assign_spans module parameter on
dahdi.ko, like dahdi_handle_device already does, to determine if legacy or udev
based configuration is being done.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>

hotplug/dahdi_span_config

@@ -26,6 +26,17 @@ set -e
 
 #echo >&2 "$0($ACTION): DEBUG($# args): '$*'"
 
+# Old driver. These scripts probably won't work anyway.
+if [ ! -f /sys/module/dahdi/parameters/auto_assign_spans ]; then
+	$LOGGER "Old driver (no auto_assign_spans parameter). Skip $DEVPATH"
+	exit 0
+fi
+
+if [ $(cat /sys/module/dahdi/parameters/auto_assign_spans) -eq 1 ]; then
+	$LOGGER "auto_assign_spans=1. Skip $DEVPATH"
+	exit 0
+fi
+
 # Do we have a configuration?
 if [ -f /etc/dahdi/init.conf ]; then
 	. /etc/dahdi/init.conf