lnstat_util: Make sure buffer is NUL-terminated

Can't use strlcpy() here since lnstat is not linked against libutil.

While being at it, fix coding style in that chunk as well.

Signed-off-by: Phil Sutter <phil@nwl.cc>

misc/lnstat_util.c

@@ -150,7 +150,8 @@ static int lnstat_scan_compat_rtstat_fields(struct lnstat_file *lf)
 {
 	char buf[FGETS_BUF_SIZE];
 
-	strncpy(buf, RTSTAT_COMPAT_LINE, sizeof(buf)-1);
+	strncpy(buf, RTSTAT_COMPAT_LINE, sizeof(buf) - 1);
+	buf[sizeof(buf) - 1] = '\0';
 
 	return __lnstat_scan_fields(lf, buf);
 }