the OUTMCAST stat is double incremented, getting bumped once in the mcast code
itself, and again in the common ip output path. Remove the mcast bump, as its
not needed
Validated by the reporter, with good results
Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Claus Jensen <claus.jensen@microsemi.com> CC: Claus Jensen <claus.jensen@microsemi.com> CC: David Miller <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net>