tradefed: boot.img may have different name

Few jobs are submmitted with boot-<kernel_version>-<commit_id>.img
format.

Change-Id: Ibd9a22df83ed8b855731e424be8f3a8ed66d299f
Signed-off-by: Vishal Bhoj <vishal.bhoj@linaro.org>
diff --git a/automated/android/tradefed/monitor_fastboot.sh b/automated/android/tradefed/monitor_fastboot.sh
index 62e066c..cdf0f49 100755
--- a/automated/android/tradefed/monitor_fastboot.sh
+++ b/automated/android/tradefed/monitor_fastboot.sh
@@ -1,4 +1,4 @@
 #!/bin/sh -x
 while true; do
-fastboot boot /lava-lxc/boot.img
+./fastboot boot /lava-lxc/boot*.img
 done