perf hists browser: Apply the dso and thread filters when merging new batches

Now that we dynamicly add entries on the timer we need to not only
traverse all entries when the user zooms into threads and/or DSOs, but
as well after that apply it to the new batches of hist entries in
hists__collapse_resort.

Reported-by: Mike Galbraith <efault@gmx.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@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-zustn633c7hnrae94x6nld1p@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>