Fix Synaptics touch FW updating typo

It looks like a linebreak "\" was accidentally removed from
chromeos-touch-update.conf and it broke FW updating for Synaptics
devices.  This CL adds the "\" back in and should fix updating for
these effected machines.

BUG=b:38395353
TEST=built on Lulu builder and the logs showed a FW update working

Change-Id: I7c3253618b8a82dd057d469d4f6b77c21b8b1011
Signed-off-by: Charlie Mooney <charliemooney@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/508165
Reviewed-by: Jingkui Wang <jkwang@google.com>
(cherry picked from commit c4c2d9ae0581b82747c079b42ab3a9969d942e83)
Reviewed-on: https://chromium-review.googlesource.com/512902
diff --git a/scripts/chromeos-touch-update.conf b/scripts/chromeos-touch-update.conf
index 8b74077..55874ad 100644
--- a/scripts/chromeos-touch-update.conf
+++ b/scripts/chromeos-touch-update.conf
@@ -55,7 +55,7 @@
           logger -t "$UPSTART_JOB" "${device_name} firmware update failed." ) &
         ;;
       "${SYNAPTICS_VENDOR_ID}")
-        ( /opt/google/touch/scripts/chromeos-synaptics-touch-firmware-update.sh
+        ( /opt/google/touch/scripts/chromeos-synaptics-touch-firmware-update.sh \
             -d "${hidname}" -r || \
           logger -t "$UPSTART_JOB" "${device_name} firmware update failed." ) &
         ;;