drop struct keyword for non-packed objects

As a style decision, struct is often used with packed structures to
indicate they are used like C-structs.  Cleanup this codebase to not use
the extra struct keyword throughout.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I2f83bb1989e4d1f2f843ba3e45fb82e04f0fa61c
diff --git a/test/pid_json_unittest.cpp b/test/pid_json_unittest.cpp
index 0e767f9..827d207 100644
--- a/test/pid_json_unittest.cpp
+++ b/test/pid_json_unittest.cpp
@@ -14,7 +14,7 @@
     // This is technically invalid.
 
     std::map<int64_t, conf::PIDConf> pidConfig;
-    std::map<int64_t, struct conf::ZoneConfig> zoneConfig;
+    std::map<int64_t, conf::ZoneConfig> zoneConfig;
 
     auto j2 = R"(
       {
@@ -33,7 +33,7 @@
     // Parse a valid configuration with one zone and one PID.
 
     std::map<int64_t, conf::PIDConf> pidConfig;
-    std::map<int64_t, struct conf::ZoneConfig> zoneConfig;
+    std::map<int64_t, conf::ZoneConfig> zoneConfig;
 
     auto j2 = R"(
       {
@@ -78,7 +78,7 @@
     // Hysteresis parameters.
 
     std::map<int64_t, conf::PIDConf> pidConfig;
-    std::map<int64_t, struct conf::ZoneConfig> zoneConfig;
+    std::map<int64_t, conf::ZoneConfig> zoneConfig;
 
     auto j2 = R"(
       {
@@ -127,7 +127,7 @@
     // Hysteresis parameters.
 
     std::map<int64_t, conf::PIDConf> pidConfig;
-    std::map<int64_t, struct conf::ZoneConfig> zoneConfig;
+    std::map<int64_t, conf::ZoneConfig> zoneConfig;
 
     auto j2 = R"(
       {