perf evlist: Renane set_filters method to apply_filters

Because that is what it really does, i.e. it applies the filters that
were parsed from the command line and stashed into the evsels they refer
to.

We'll need the set_filter method name to actually apply a filter to all
the evsels in an evlist, for instance, to ask that a syswide tracer
doesn't trace itself.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-v9x3q9rv4caxtox7wtjpchq5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>