This makes it work with non-GNU grep's as well.
Signed-off-by: NJohn Spencer <maillist-linux@barfooze.de>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://thread.gmane.org/gmane.linux.kernel.perf.user/1686Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>