Script that this patch modifies and usb_modeswitch_dispatcher Tcl script
that is being called by it both need a writable temporary directory which
is a problematic requirement for example if usb_modeswitch is triggered
by a module loaded during system startup.
Fortunately, /run is available very early at boot so let's redirect them
there instead.

--- a/usb_modeswitch.sh	2016-11-29 17:29:47.000000000 +0100
+++ b/usb_modeswitch.sh	2016-11-30 01:11:51.747993839 +0100
@@ -17,6 +17,8 @@
 	return 0
 }
 
+export TMPDIR=/run
+
 if [ $(expr "$1" : "--.*") ]; then
 	p_id=$4
 	if [ -z $p_id ]; then