LU-17251 tests: force test_rr_alloc new seq

LU-17251 tests: force test_rr_alloc new seq

Force parallel-scale test_rr_alloc to create a new OST sequence
if the number of precreated objects is low.  This should ensure
that the number of available objects is enough to complete the
test, and avoids OST object creation being blocked in the middle
of the test while the SEQ number rolls over.

Test-Parameters: trivial
Test-Parameters: testgroup=review-dne-part-9 env=RACER_EXCEPT="1 2"
Test-Parameters: testgroup=review-dne-part-9 env=RACER_EXCEPT="1 2"
Test-Parameters: testgroup=review-dne-part-9 env=RACER_EXCEPT="1 2"
Test-Parameters: testgroup=review-dne-part-9 env=RACER_EXCEPT="1 2"
Test-Parameters: testgroup=review-dne-part-9 env=RACER_EXCEPT="1 2"
Test-Parameters: testgroup=review-dne-part-9 env=RACER_EXCEPT="1 2"
Test-Parameters: testgroup=review-dne-part-9 env=RACER_EXCEPT="1 2"
Test-Parameters: testgroup=review-dne-part-9 env=RACER_EXCEPT="1 2"
Test-Parameters: testgroup=review-dne-part-9 env=RACER_EXCEPT="1 2"
Test-Parameters: testgroup=review-dne-part-9 env=RACER_EXCEPT="1 2"
Test-Parameters: testlist=parallel-scale env=ONLY=rr_alloc,ONLY_REPEAT=50
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I636a488e575d27ac235749911f171d5e1e3ebbe5
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56913
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Li Dongyang <dongyangli@ddn.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>