kern/58070: rump prints unnecessary "entropy: ready" message when otherwise silent

[campbell+netbsd%mumble.net@localhost]

>Number:         58070
>Category:       kern
>Synopsis:       rump prints unnecessary "entropy: ready" message when otherwise silent
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Mar 23 19:25:00 +0000 2024
>Originator:     Taylor R Campbell
>Release:        current, 10
>Organization:
The RumpBSD Entmoot
>Environment:
>Description:
Rump kernels which are normally silent, without RUMP_VERBOSE enabled, nevertheless often print the single line "entropy: ready".

The message is helpful for hard kernels, but not really for rump kernels, which pretty much always just draw entropy from the host's /dev/urandom or equivalent via the rump hyperentropy source.
>How-To-Repeat:
run anything with rump, like atf tests
>Fix:
Yes, please!

Maybe printf should be replaced by aprint_normal or something, not sure offhand what mechanism will serve best to print output in a hard kernel but suppress it in a rump kernel.