Add the '-p4' options when exemplifying the module compilation

Add the '-p4' options when exemplifying the module compilation

Currently the example command which supposedly should compile the
instrumentation module is missing the '-p4' option, meaning that
upon running it will compile and run the module. In order to make
the command more in sync with what this particular chapter is about,
add the -p4 options so that after running the command the user gets
to copy the resulting module.

Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>