perf tools: Check $HOME/.perfconfig ownership

Just like we do already for perf.data files.

Requested-by: Ingo Molnar <mingo@elte.hu>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Christian Ohm <chr.ohm@gmx.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jonathan Nieder <jrnieder@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
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-qgokmxsmvppwpc5404qhyk7e@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>