Change boot_fail_threshold to 0.

The majority of users will benefit from boot_fail_threshold of 0
which means that if any boot fails, the whole run is considered a
failure.

Change-Id: If07f11fe4f102b7819b8ed10548d076a28dfad05
Signed-off-by: Michael Walsh <micwalsh@us.ibm.com>
diff --git a/extended/obmc_boot_test_resource.robot b/extended/obmc_boot_test_resource.robot
index f3ffaa5..6c64da8 100644
--- a/extended/obmc_boot_test_resource.robot
+++ b/extended/obmc_boot_test_resource.robot
@@ -55,7 +55,7 @@
 ${power_off_timeout}        2 mins
 # If the number of boot failures, exceeds boot_fail_threshold, this program
 # returns non-zero.
-${boot_fail_threshold}      ${1000000}
+${boot_fail_threshold}      ${0}
 ${test_mode}                0
 ${quiet}                    0
 ${debug}                    0