kprobes: Add assertions for required lock

Add assertions for required locks instead of comment it
so that the lockdep can inspect locks automatically.

Link: https://lkml.kernel.org/r/163163039572.489837.18011973177537476885.stgit@devnote2



Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>