tools lib traceevent: Let filtering numbers by string use function names

tools lib traceevent: Let filtering numbers by string use function names

As a pointer can be converted into a function name, let the filters
work with the function name as well as with the pointer number.  If
the comparison expects a string, then convert numbers into functions,
but only when the number is the same size as a long.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-oxsa1qkr2eq7u8d7r0aapedu@git.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>