test/hash: fix buffer overflow with jhash

test/hash: fix buffer overflow with jhash

This patch fixes buffer overflow reported by ASAN,
please reference https://bugs.dpdk.org/show_bug.cgi?id=818

Some tests for the rte_hash table use the rte_jhash_32b() as
the hash function. This hash function interprets the length
argument in units of 4 bytes.

This patch adds a wrapper function around rte_jhash_32b()
to reflect API differences regarding the length argument,
effectively dividing it by 4.

For some tests rte_jhash() is used with keys of length not
a multiple of 4 bytes. From the rte_jhash() documentation:
If input key is not aligned to four byte boundaries or a
multiple of four bytes in length, the memory region just
after may be read (but not used in the computation).

This patch increases the size of the proto field of the
flow_key struct up to uint32_t.

Bugzilla ID: 818
Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org
Signed-off-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
Acked-by: Yipeng Wang <yipeng1.wang@intel.com>