ftrace, kbuild: condense recordmcount.pl parameter code

Impact: cleanup

Sam Ravnborg pointed out that I could condense the code for the parameters of
recordmcount.pl by using an $(if ...) condition.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>