netem: missing break in ge loss generator

There is a missing break statement in the Gilbert Elliot loss model
generator which makes state machine behave incorrectly.

Reported-by: Martin Burri <martin.burri@ch.abb.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>