perf script: Simplify auxiliary event printing functions

This simplifies the print functions for the following perf script
options:

	--show-task-events
	--show-namespace-events
	--show-cgroup-events
	--show-mmap-events
	--show-switch-events
	--show-lost-events
	--show-bpf-events

Example:
	# perf record --switch-events -a -e cycles -c 10000 sleep 1
 Before:
	# perf script --show-task-events --show-namespace-events --show-cgroup-events --show-mmap-events --show-switch-events --show-lost-events --show-bpf-events > out-before.txt
 After:
	# perf script --show-task-events --show-namespace-events --show-cgroup-events --show-mmap-events --show-switch-events --show-lost-events --show-bpf-events > out-after.txt
	# diff -s out-before.txt out-after.txt
	Files out-before.txt and out-after.tx are identical
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200402141548.21283-1-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>