Add loop module kernel message filter

Now that we're not setting up per-mount loopback devices we can not have
the loop module loaded until tests are running.

Signed-off-by: Zach Brown <zab@versity.com>

tests/funcs/filter.sh

@@ -86,6 +86,7 @@ t_filter_dmesg()
 	re="$re|scoutfs .* critical transaction commit failure.*"
 
 	# change-devices causes loop device resizing
+	re="$re|loop: module loaded"
 	re="$re|loop[0-9].* detected capacity change from.*"
 
 	# ignore systemd-journal rotating