Update OPENBMC_MODEL if it fails to get from BMC

Test suites can be executed with different local user privilege.
Specially to execute boot plugin, the boot infrastructure requires
OPENBMC_MODEL to be poplated.

Currently, this model is fetch from BMC via SSH, however, different
privilege user will not have the admin or root access causing the
boot setup to fail.

Change-Id: I0a013b622c52cc3f33f2870779b996dac1b3f11a
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/lib/obmc_boot_test.py b/lib/obmc_boot_test.py
index 920d14d..0dc245d 100755
--- a/lib/obmc_boot_test.py
+++ b/lib/obmc_boot_test.py
@@ -488,8 +488,12 @@
     global openbmc_model
     if openbmc_model == "":
         status, ret_values =\
-            grk.run_key_u("Get BMC System Model")
-        openbmc_model = ret_values
+            grk.run_key_u("Get BMC System Model", ignore=1)
+        # Set the model to default "OPENBMC" if getting it from BMC fails.
+        if status == 'FAIL':
+            openbmc_model = 'OPENBMC'
+        else:
+            openbmc_model = ret_values
         BuiltIn().set_global_variable("${openbmc_model}", openbmc_model)
     gv.set_exit_on_error(True)
     gv.valid_value(openbmc_host)