perf: Make -f the default for perf record

Force the overwriting mode by default if append mode is not explicit.
Adding -f every time one uses perf on a daily basis quickly becomes a
burden.

Keep the -f among the options though to avoid breaking some random
users scripts.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>

tools/perf/Documentation/perf-record.txt

@@ -58,7 +58,7 @@ OPTIONS
 
 -f::
 --force::
-	Overwrite existing data file.
+	Overwrite existing data file. (deprecated)
 
 -c::
 --count=::