selftests/ftrace: Expand the tprobe event test to check wrong format

Expand the tprobe event test case to check wrong tracepoint
format.

Link: https://lore.kernel.org/all/174055076681.4079315.16941322116874021804.stgit@mhiramat.tok.corp.google.com/



Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>