liblog: cleanup TODOs in tests

1) log_msg.msg() will never be nullptr, unless logd sends an invalid
   response, so it's the right idea to ASSERT() that this is true
   instead of just checking and continuing.
2) Even though liblog.too_big_payload is tautological, there's no
   reason not to test it, in case the assumptions that make it
   tautological change.
3) We're not too worried about the return value of logging functions
   or that liblog prevents them from being written (anyone can write
   their own values to logd after all).

Test: liblog-unit-tests
Change-Id: I144cc7cf45c164ea5f04e0786ff0e298fd626f07
diff --git a/liblog/tests/liblog_test.cpp b/liblog/tests/liblog_test.cpp
index a031531..048bf61 100644
--- a/liblog/tests/liblog_test.cpp
+++ b/liblog/tests/liblog_test.cpp
@@ -97,10 +97,7 @@
     ASSERT_EQ(log_buffer, log_msg.id());
     ASSERT_EQ(pid, log_msg.entry.pid);
 
-    // TODO: Should this be an assert?
-    if (log_msg.msg() == nullptr) {
-      continue;
-    }
+    ASSERT_NE(nullptr, log_msg.msg());
 
     check_message(log_msg, &found);
   }
@@ -121,10 +118,7 @@
     ASSERT_EQ(log_buffer, log_msg.id());
     ASSERT_EQ(pid, log_msg.entry.pid);
 
-    // TODO: Should this be an assert?
-    if (log_msg.msg() == nullptr) {
-      continue;
-    }
+    ASSERT_NE(nullptr, log_msg.msg());
 
     found = false;
     check_message(log_msg, &found);
@@ -1031,7 +1025,7 @@
 #endif
 }
 
-// TODO: This test is tautological. android_logger_list_read() calls recv() with
+// Note: This test is tautological. android_logger_list_read() calls recv() with
 // LOGGER_ENTRY_MAX_PAYLOAD as its size argument, so it's not possible for this test to read a
 // payload larger than that size.
 TEST(liblog, too_big_payload) {
@@ -1982,7 +1976,6 @@
 #endif
 }
 
-// TODO: Do we need to check that we didn't actually write anything if we return a failure here?
 TEST(liblog,
      android_errorWriteWithInfoLog__android_logger_list_read__null_data) {
 #ifdef __ANDROID__