catch exceptions as const

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ia4086e77ad205e9a6a73a6ca570036818e3069fe
diff --git a/src/oemcommands.cpp b/src/oemcommands.cpp
index d4835f1..d06bb17 100644
--- a/src/oemcommands.cpp
+++ b/src/oemcommands.cpp
@@ -379,7 +379,7 @@
             data = result;
             return 0;
         }
-        catch (std::bad_variant_access& e)
+        catch (const std::bad_variant_access& e)
         {
             phosphor::logging::log<phosphor::logging::level::ERR>(e.what());
             return -1;