netdev-dpdk: Refactor tunnel checksum offloading. #590

Job	Run time
osx clang --disable-ssl	3m 18s
dpdk gcc	5s
linux rpm fedora	4m 38s
linux deb no dpdk	4m 18s
clang-analyze	9m 55s
linux gcc --disable-ssl	2m 30s
linux clang --disable-ssl	2m 24s
linux gcc c99	2m 36s
linux clang c99	2m 39s
linux gcc test	8m 35s
linux clang address,undefined test	16m 10s
linux gcc test --enable-shared	11m 32s
linux clang test --enable-shared	11m 13s
linux gcc check check-dpdk dpdk	18m 34s
linux clang check check-dpdk dpdk	17m 23s
linux gcc test -ljemalloc	9m 15s
linux clang test -ljemalloc	8m 43s
linux gcc --enable-afxdp	2m 19s
linux clang --enable-afxdp	2m 40s
linux gcc dpdk --enable-shared	3m 29s
linux clang dpdk --enable-shared	3m 29s
linux gcc dpdk-shared	2m 50s
linux clang dpdk-shared	2m 40s
linux gcc dpdk-shared --enable-shared	3m 21s
linux clang dpdk-shared --enable-shared	3m 23s
linux gcc m32 --disable-ssl	2m 58s
linux gcc check-ovsdb-cluster	6m 36s
linux gcc check-kernel -100	8m 47s
linux gcc check-kernel 100-	9m 2s
linux clang address,undefined check-kernel -100	11m 35s
linux clang address,undefined check-kernel 100-	11m 39s
linux gcc check-offloads -100	9m 6s
linux gcc check-offloads 100-	7m 28s
linux gcc dpdk check-system-userspace	10m 54s
linux clang address,undefined dpdk check-system-userspace	14m 23s
linux gcc dpdk check-system-tso	10m 52s
linux gcc dpdk check-afxdp	10m 49s
	4h 32m 8s

Provide feedback