ktest: Fix breakage from change of oldnoconfig to olddefconfig

Commit fb16d891 "kconfig: replace 'oldnoconfig' with 'olddefconfig', and
keep the old name", changed ktest's default config update from
oldnoconfig to olddefconfig without adding oldnoconfig as a backup.
The make oldnoconfig works much better than its backup of:
   yes '' | make oldconfig

But due to this change, and the fact that ktest is used to build lots of
older kernels (and for bisects), it forgoes the oldnoconfig completely.

Cc: Adam Lee <adam8157@gmail.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

tools/testing/ktest/ktest.pl

@@ -1966,10 +1966,14 @@ sub make_oldconfig {
 
     if (!run_command "$make olddefconfig") {
 	# Perhaps olddefconfig doesn't exist in this version of the kernel
-	# try a yes '' | oldconfig
-	doprint "olddefconfig failed, trying yes '' | make oldconfig\n";
-	run_command "yes '' | $make oldconfig" or
-	    dodie "failed make config oldconfig";
+	# try oldnoconfig
+	doprint "olddefconfig failed, trying make oldnoconfig\n";
+	if (!run_command "$make oldnoconfig") {
+	    doprint "oldnoconfig failed, trying yes '' | make oldconfig\n";
+	    # try a yes '' | oldconfig
+	    run_command "yes '' | $make oldconfig" or
+		dodie "failed make config oldconfig";
+	}
     }
 }