Enable cppcoreguidelines-init-variables

We try to enforce this rule, but clearly the robot can do a better job.
Enable the rule, and for init of all variables that clang-tidy finds in
error.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Icf64bc51b3180de29f7e92fa5c5f636e6b1462a6
diff --git a/src/PSUSensorMain.cpp b/src/PSUSensorMain.cpp
index ae7afc3..28d37ff 100644
--- a/src/PSUSensorMain.cpp
+++ b/src/PSUSensorMain.cpp
@@ -324,7 +324,6 @@
             continue;
         }
 
-        const std::string* psuName;
         auto directory = pmbusPath.parent_path();
 
         auto ret = directories.insert(directory.string());
@@ -399,10 +398,9 @@
                 continue;
             }
 
-            const uint64_t* confBus;
-            const uint64_t* confAddr;
-            if (!(confBus = std::get_if<uint64_t>(&(configBus->second))) ||
-                !(confAddr = std::get_if<uint64_t>(&(configAddress->second))))
+            const uint64_t* confBus = std::get_if<uint64_t>(&(configBus->second));
+            const uint64_t* confAddr = std::get_if<uint64_t>(&(configAddress->second));
+            if (confBus == nullptr || confAddr == nullptr)
             {
                 std::cerr
                     << "Cannot get bus or address, invalid configuration\n";
@@ -442,8 +440,8 @@
                       << deviceName << "\n";
             continue;
         }
-
-        if (!(psuName = std::get_if<std::string>(&(findPSUName->second))))
+        const std::string* psuName = std::get_if<std::string>(&(findPSUName->second));
+        if (psuName == nullptr)
         {
             std::cerr << "Cannot find psu name, invalid configuration\n";
             continue;