Disallow start chassis state of "on" for "OBMC Reboot".

Currently, rebooting from an "on" state is not supported.

Change-Id: I37f55e5334d79972b3eaef741a350f61f396684a
Signed-off-by: Michael Walsh <micwalsh@us.ibm.com>
diff --git a/data/boot_table.json b/data/boot_table.json
index 4f988ba..0c69f2b 100644
--- a/data/boot_table.json
+++ b/data/boot_table.json
@@ -43,7 +43,7 @@
     # Run a "reboot" on the OBMC..
     "OBMC Reboot": {
         "start": {
-            "chassis": "^Off|On$"
+            "chassis": "^Off$"
         },
         "end": {
             "chassis": "^Off$",