Skip newlines for SELinux logs

libselinux log messages usually end with a new line character. Android
log system does not require the new line character and will include the
character as-is in the log buffer.

This trimming was already implemented when the message is typed as
SELINUX_AVC (see SelinuxAvcLog). Move the truncation one level up so it
is occurring for all types of logs.

Test: boot & adb logcat & inspect SELinux logs
Change-Id: I360359c1b178ef24d555dd41f8d4a18b293a175c