tracing: Remove dummy options and flags

tracing: Remove dummy options and flags

When a tracer does not define their own flags, dummy options and flags are
used so that the values are always valid. There's not that many locations
that reference these values so having dummy versions just complicates the
code. Remove the dummy values and just check for NULL when appropriate.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://patch.msgid.link/20251105161935.206093132@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>