[moblab] Add -v param to the readlink for debugging.

readlink seems to fail every 10-15 bootups on the vm.  Add the
-v param to see if we can determine the root cause of why it is
failing.

BUG=chromium:929438
TEST=inspection

Change-Id: I0e2ef4211d9dc77f71c89c0a83c0cee32fcbcc3a
Reviewed-on: https://chromium-review.googlesource.com/1482070
Commit-Ready: Keith Haddow <haddowk@chromium.org>
Tested-by: Keith Haddow <haddowk@chromium.org>
Reviewed-by: Matt Mallett <mattmallett@chromium.org>
diff --git a/src/upstart_init/moblab-external-storage-init.conf b/src/upstart_init/moblab-external-storage-init.conf
index 50f81ae..796f6c3 100644
--- a/src/upstart_init/moblab-external-storage-init.conf
+++ b/src/upstart_init/moblab-external-storage-init.conf
@@ -30,7 +30,7 @@
   # denied ), report the error messages from readlink but continue as if no
   # usb drive has been found.
   sleep 1
-  usb_drive=$(readlink -f /dev/disk/by-label/MOBLAB-STORAGE) ||
+  usb_drive=$(readlink -v -f /dev/disk/by-label/MOBLAB-STORAGE) ||
       echo "Readlink failed code $?"
   if [ ! -e "${usb_drive}" ] &&
          [ ${diskspace} -lt ${MIN_STATEFUL_DISKSPACE} ]; then
@@ -38,7 +38,7 @@
     logger -t "${UPSTART_JOB}" "Retrying search for usb disk"
     # This may force a rescan of all the USB devices.
     lsusb -v
-    usb_drive=$(readlink -f /dev/disk/by-label/MOBLAB-STORAGE) ||
+    usb_drive=$(readlink -v -f /dev/disk/by-label/MOBLAB-STORAGE) ||
         echo "Readlink failed code $?"
   fi
   if [ -e "${usb_drive}" ]; then