LU-12218 ptlrpc: Bulk assertion fails on -ENOMEM

LU-12218 ptlrpc: Bulk assertion fails on -ENOMEM

Recalculate rq_mbits on ENOMEM resend if OBD_CONNECT_BULK_MBITS
isn't used.

Change-Id: I3bd5f7536372558a264bf5fe3247b8b1946f84fd
Cray-bug-id: LUS-7159
Signed-off-by: Andriy Skulysh <c17819@cray.com>
Reviewed-by: Alexander Boyko <c17825@cray.com>
Reviewed-by: Andrew Perepechko <c17827@cray.com>
Reviewed-on: https://review.whamcloud.com/34753
Tested-by: Jenkins
Reviewed-by: Alexandr Boyko <c17825@cray.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>