perf symbols: Remove BIONIC wrapper around libgen.h

Now that the 2 offenders are fixed, the BIONIC conditional around
libgen.h can be removed.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Irina Tirdea <irina.tirdea@gmail.com>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/1347116812-93646-4-git-send-email-dsahern@gmail.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>