logd: log_strtok_r deal with nuls

Rename to log_strntok_r and change from dealing with strings
to dealing with a string and an associated length.

Bug: 23517551
Change-Id: Ia72f1305a53f55eeef9861ac378fb8205fd2378e
diff --git a/logd/LogKlog.h b/logd/LogKlog.h
index 7e4fde0..b0ea864 100644
--- a/logd/LogKlog.h
+++ b/logd/LogKlog.h
@@ -21,7 +21,7 @@
 #include <log/log_read.h>
 #include "LogReader.h"
 
-char *log_strtok_r(char *str, char **saveptr);
+char *log_strntok_r(char *s, size_t *len, char **saveptr, size_t *sublen);
 
 class LogKlog : public SocketListener {
     LogBuffer *logbuf;