dpdk: update DPDK submodule to e42a05c

Add "linuxapp, eal: Fix the memory leak issue of logid"

Change-Id: I6b2a025a6dda1c98fbd4f22ce5cbbc7c34ad3139
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/365548


Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>