lib/plist.c: make plist test announcements KERN_DEBUG
They show up in dmesg
[ 4.041094] start plist test
[ 4.045804] end plist test
without a lot of meaning so hide them behind debug loglevel.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>