perf archive: Remove duplicated 'runs' in man page

Two 'runs' here breaks the sentence in Description of 'perf archive'
command.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/78a15a9f4f500b6074a1e25917d6e8251f894628.1386629050.git.yangds.fnst@cn.fujitsu.com


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