Fix clang-tidy warnings in log_time.h

 - Zero initialize log_time instances by default
 - Disable implicit conversions by making constructors explicit
 - Explicitly initialize to EPOCH in most places
 - Change sniffTime() to avoid in-place modification of a log_time

I stopped here, but we could consider following up with a more invasive
change to make log_time instances immutable and perhaps also remove the
default constructor to force explicit initialization to EPOCH.

Test: atest libbase_test netd_unit_test
Change-Id: I67e716ef74adaaf40ab2c6e2e0dddb8d309bc7ca
diff --git a/logd/LogKlog.h b/logd/LogKlog.h
index bb92dd2..6bfd6a8 100644
--- a/logd/LogKlog.h
+++ b/logd/LogKlog.h
@@ -55,11 +55,10 @@
     }
 
    protected:
-    void sniffTime(log_time& now, const char*& buf, ssize_t len, bool reverse);
-    pid_t sniffPid(const char*& buf, ssize_t len);
-    void calculateCorrection(const log_time& monotonic, const char* real_string,
-                             ssize_t len);
-    virtual bool onDataAvailable(SocketClient* cli);
+     log_time sniffTime(const char*& buf, ssize_t len, bool reverse);
+     pid_t sniffPid(const char*& buf, ssize_t len);
+     void calculateCorrection(const log_time& monotonic, const char* real_string, ssize_t len);
+     virtual bool onDataAvailable(SocketClient* cli);
 };
 
 #endif