This patch adds missing backslash in host's testpmd command
line.
Without it the command works, but a single core is used
instead of four, which might create confusion.
Fixes: 58a2551a160f ("doc: introduce PVP reference benchmark")
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: John McNamara <john.mcnamara@intel.com>