Use the dso__insert_symbol function instead of symbols__insert() in
order to properly update the dso symbol cache.

If the cache is not updated, then duplicate symbols can be
unintentionally created, inserted, and exported.

This change prevents duplicate symbols from being exported due to
dso__find_symbol() using a stale symbol cache.
Signed-off-by: NChris Phlipot <cphlipot0@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1462937209-6032-3-git-send-email-cphlipot0@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>