Don't check 1-node logfiles when no data is sent on other channels

Single nodes are considered multi-nodes with node count=1. Since there
is no inter-node communication, unless data is sent on any channel, no
readable logs are generated. Noticed when AOS config test for a
single node test stand failed.

Change-Id: Iefa00dc61faeca3297ffc059769b6dcd9ee48f74
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/aos/util/config_validator_lib.cc b/aos/util/config_validator_lib.cc
index 0f90ed6..2bd660a 100644
--- a/aos/util/config_validator_lib.cc
+++ b/aos/util/config_validator_lib.cc
@@ -177,6 +177,11 @@
   const std::string log_path = aos::testing::TestTmpDir() + "/logs/";
   for (const bool send_data_on_channels : {false, true}) {
     SCOPED_TRACE(send_data_on_channels);
+    // Single nodes (multi-nodes with node count = 1) will not produce readable
+    // logs in the absense of data.
+    if (!send_data_on_channels && (configuration::NodesCount(config) == 1u)) {
+      continue;
+    }
     for (const LoggerNodeSetValidation *logger_set :
          *validation_config->logging()->logger_sets()) {
       SCOPED_TRACE(aos::FlatbufferToJson(logger_set));