catch exceptions as const

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: If6aba71f482f75143e6d669763b8853db22318cf
diff --git a/power-sequencer/pgood_monitor.cpp b/power-sequencer/pgood_monitor.cpp
index 3c74fdb..d86acef 100644
--- a/power-sequencer/pgood_monitor.cpp
+++ b/power-sequencer/pgood_monitor.cpp
@@ -114,7 +114,7 @@
 
         return timer.get_event().loop();
     }
-    catch (std::exception& e)
+    catch (const std::exception& e)
     {
         log<level::ERR>(e.what());
         log<level::ERR>("Unexpected failure prevented PGOOD checking");