mesh: Fix confusing language in log messages
mesh: Fix confusing language in log messages

Both "store" and "clear" are verbs, so putting them after each other
is just confusing. Use "clean" consistently when clearing settings
entries.

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble