logd: turn on -Werror

- Deal with some -Wunused / -Wunused-variable issues

Change-Id: Ic86cd7b0680868ad0536198b71a34cb19134fc21

logd/Android.mk

@@ -25,7 +25,7 @@ LOCAL_SHARED_LIBRARIES := \
     libcutils \
     libutils
 
-LOCAL_MODULE_TAGS := optional
+LOCAL_CFLAGS := -Werror
 
 include $(BUILD_EXECUTABLE)
 

logd/CommandListener.cpp

@@ -208,7 +208,6 @@ int CommandListener::GetStatisticsCmd::runCommand(SocketClient *cli,
                                          int argc, char **argv) {
     setname();
     uid_t uid = cli->getUid();
-    gid_t gid = cli->getGid();
     if (clientHasLogCredentials(cli)) {
         uid = AID_ROOT;
     }

logd/tests/logd_test.cpp

@@ -196,8 +196,6 @@ TEST(logd, statistics) {
 
     cp = strstr(cp, "Minimum time between log events per dgram_qlen:");
 
-    char *log_events_per_span = cp;
-
     if (cp) {
         while (*cp && (*cp != '\n')) {
             ++cp;
@@ -462,7 +460,7 @@ TEST(logd, both) {
             dump_log_msg("user", &msg, 3, -1);
         }
 
-        alarm(0);
+        alarm(old_alarm);
         sigaction(SIGALRM, &old_sigaction, NULL);
 
         close(fd);