pseq: Add generic failure handling to base class

Use the power sequencer base class to handle failure cases where the
device is not found or a device specific failure can not determined. Add
a error logging convience method. Move the D-Bus object to the base
class.

Signed-off-by: Jim Wright <jlwright@us.ibm.com>
Change-Id: I6f7c2951e83cb892ec0c63018d65d5e241ebe6f0
diff --git a/phosphor-power-sequencer/src/power_control.hpp b/phosphor-power-sequencer/src/power_control.hpp
index 1bac68c..5bd5e47 100644
--- a/phosphor-power-sequencer/src/power_control.hpp
+++ b/phosphor-power-sequencer/src/power_control.hpp
@@ -75,8 +75,7 @@
     /**
      * The power sequencer device to monitor.
      */
-    std::unique_ptr<PowerSequencerMonitor> device{
-        std::make_unique<PowerSequencerMonitor>()};
+    std::unique_ptr<PowerSequencerMonitor> device;
 
     /**
      * Indicates if a specific power sequencer device has already been found.