The name of the file with additional kernel options must include
the kernel series name. Otherwise the script in kernel/Dockerfile
will not apply it. So the example file name should be
`config-4.9.x-x86_64-foo` instead of `config-foo`.
@@ -160,7 +160,7 @@ The kernel build system has some provision to allow local
customisation to the build.
If you want to override/add some kernel config options, you can add a
-file called `config-foo` and then invoke the build with `make
+file called `config-4.9.x-x86_64-foo` and then invoke the build with `make
EXTRA=-foo build_4.9.x-foo` and this will build an image with the
additional kernel config options enabled.
