liblog: add -Wall,-Wextra and do related clean-up.

Test: build
Change-Id: I3b33f2b896cb8bf7ad9edf110d1739d559028282
diff --git a/liblog/logger_write.cpp b/liblog/logger_write.cpp
index 4fbab4b..aef9e04 100644
--- a/liblog/logger_write.cpp
+++ b/liblog/logger_write.cpp
@@ -39,13 +39,6 @@
 static int __write_to_log_init(log_id_t, struct iovec* vec, size_t nr);
 static int (*write_to_log)(log_id_t, struct iovec* vec, size_t nr) = __write_to_log_init;
 
-/*
- * This is used by the C++ code to decide if it should write logs through
- * the C code.  Basically, if /dev/socket/logd is available, we're running in
- * the simulator rather than a desktop tool and want to use the device.
- */
-static enum { kLogUninitialized, kLogNotAvailable, kLogAvailable } g_log_status = kLogUninitialized;
-
 static int check_log_uid_permissions() {
 #if defined(__ANDROID__)
   uid_t uid = __android_log_uid();
@@ -104,22 +97,6 @@
   }
 }
 
-extern "C" int __android_log_dev_available() {
-  struct android_log_transport_write* node;
-
-  if (list_empty(&__android_log_transport_write)) {
-    return kLogUninitialized;
-  }
-
-  write_transport_for_each(node, &__android_log_transport_write) {
-    __android_log_cache_available(node);
-    if (node->logMask) {
-      return kLogAvailable;
-    }
-  }
-  return kLogNotAvailable;
-}
-
 #if defined(__ANDROID__)
 static atomic_uintptr_t tagMap;
 #endif
@@ -228,13 +205,6 @@
   return ret;
 }
 
-/*
- * Extract a 4-byte value from a byte stream. le32toh open coded
- */
-static inline uint32_t get4LE(const uint8_t* src) {
-  return src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
-}
-
 static int __write_to_log_daemon(log_id_t log_id, struct iovec* vec, size_t nr) {
   struct android_log_transport_write* node;
   int ret, save_errno;
@@ -302,7 +272,7 @@
       }
     }
     if (m && (m != (EventTagMap*)(uintptr_t)-1LL)) {
-      tag = android_lookupEventTag_len(m, &len, get4LE(static_cast<uint8_t*>(vec[0].iov_base)));
+      tag = android_lookupEventTag_len(m, &len, *static_cast<uint32_t*>(vec[0].iov_base));
     }
     ret = __android_log_is_loggable_len(ANDROID_LOG_INFO, tag, len, ANDROID_LOG_VERBOSE);
     if (f) { /* local copy marked for close */