cleanup: add missing explicit to constructors

For constructors with a single argument, mark explicit.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I4a57fb3f7bdab1fc7065399b47af262970443599
diff --git a/dbus/dbuspassiveredundancy.hpp b/dbus/dbuspassiveredundancy.hpp
index 3d7e2a6..7330baa 100644
--- a/dbus/dbuspassiveredundancy.hpp
+++ b/dbus/dbuspassiveredundancy.hpp
@@ -31,7 +31,7 @@
 class DbusPassiveRedundancy
 {
   public:
-    DbusPassiveRedundancy(sdbusplus::bus::bus& bus);
+    explicit DbusPassiveRedundancy(sdbusplus::bus::bus& bus);
     const std::set<std::string>& getFailed(void);
 
   private:
diff --git a/errors/exception.hpp b/errors/exception.hpp
index cc1bd07..9f2f2bc 100644
--- a/errors/exception.hpp
+++ b/errors/exception.hpp
@@ -6,7 +6,7 @@
 class SensorBuildException : public std::exception
 {
   public:
-    SensorBuildException(const std::string& message) : message(message)
+    explicit SensorBuildException(const std::string& message) : message(message)
     {
     }
 
@@ -22,7 +22,8 @@
 class ControllerBuildException : public std::exception
 {
   public:
-    ControllerBuildException(const std::string& message) : message(message)
+    explicit ControllerBuildException(const std::string& message) :
+        message(message)
     {
     }
 
@@ -38,7 +39,8 @@
 class ConfigurationException : public std::exception
 {
   public:
-    ConfigurationException(const std::string& message) : message(message)
+    explicit ConfigurationException(const std::string& message) :
+        message(message)
     {
     }