Large number of "Create bucket [magma] failed"

MB-37678 tracks cbcollects on magma systems being large. One contributor is the large number of files associated with magma that are listed in the cbcollect....tracked by MB37678.

While looking for other contributors I see a large number of bucket create failures which lead to increased size in memcached.log, ns_server.debug.log, and ns_server.report.log.

Here's the cbcollect that Perry reported in MB-37678:
https://s3.amazonaws.com/cb-engineering/perry/magma-warmup-finished/collectinfo-2020-02-01T154757-ns_1%40ec2-34-210-32-106.us-west-2.compute.amazonaws.com.zip

As I'm not sure if these are expected errors or not I'm assigning this ticket to the magma folks as a start.