kdb: Remove all references to DOING_KGDB2

The DOING_KGDB2 was originally a state variable for one of the two
ways to automatically transition from kdb to kgdb.  Purge all these
variables and just use one single state for the transition.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index b33116e..63786e7 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1386,7 +1386,7 @@
 		}
 
 		if (result == KDB_CMD_KGDB) {
-			if (!(KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)))
+			if (!KDB_STATE(DOING_KGDB))
 				kdb_printf("Entering please attach debugger "
 					   "or use $D#44+ or $3#33\n");
 			break;