event/dsw: remove unnecessary read barrier
event/dsw: remove unnecessary read barrier

Remove unnecessary read barrier (and misleading comment) on control
message dequeue.

Fixes: f6257b22e767 ("event/dsw: add load balancing")
Cc: stable@dpdk.org

Suggested-by: Ola Liljedahl <6d19e6e0076f8797cfccb58ffb99074265221b72@arm.com>
Signed-off-by: Mattias Rönnblom <ba23a026ae54c0c95a377f3421ce76e4585cf9f8@ericsson.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk