libs/foreignmem: Drop useless and/or misleading logging

libs/foreignmem: Drop useless and/or misleading logging

These log lines are all in response to single system calls, and do not provide
any information which the immediate caller can't determine themselves.  It is
however rude to put junk like this onto stderr, especially as system call
failures are not even error conditions in certain circumstances.

The FreeBSD logging has stale function names in, and Solaris shouldn't have
passed code review to start with.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Ian Jackson <iwj@xenproject.org>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>