test: Make test independent of the recirc_id

test: Make test independent of the recirc_id

Commit 8ae8176fd0d8ed919e3301cc961dcf02b65ff49d (tests: Make test
independent of the hash function) improves the test "ofprot-dpif
- balance-tcp bonding, different recirc flow" to not dependent on
the values of dp-hash, but it still depends on the value of recirc_id,
which can be a different value based on runs, specifically, it depends
which one of the two bonds allocates recirc id first.

Since both dp_hash and recirc_id values are runtime dependent,
consolidate the masking scripts into ofctl_strip.

Bug-report: http://openvswitch.org/pipermail/discuss/2015-October/019269.html
Reported-by: Gerhrd Stenzel <gstenzel@linux.vnet.ibm.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>