catch exceptions as const

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ia9932efb6a9335e80b3f2376d2d62e1b65866f44
diff --git a/src/biosconfigcommands.cpp b/src/biosconfigcommands.cpp
index 31c1425..a1ada8e 100644
--- a/src/biosconfigcommands.cpp
+++ b/src/biosconfigcommands.cpp
@@ -203,7 +203,7 @@
                 "org.freedesktop.DBus.Properties", "Get",
                 "xyz.openbmc_project.BIOSConfig.Manager", "PendingAttributes");
     }
-    catch (std::exception& ex)
+    catch (const std::exception& ex)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(ex.what());
         return false;
@@ -417,7 +417,7 @@
 
             return true;
         }
-        catch (std::exception& ex)
+        catch (const std::exception& ex)
         {
             phosphor::logging::log<phosphor::logging::level::ERR>(ex.what());
         }
@@ -532,7 +532,7 @@
                 "Failed to get bios base table");
         }
     }
-    catch (std::exception& ex)
+    catch (const std::exception& ex)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(ex.what());
         return false;
@@ -645,7 +645,7 @@
     {
         getChannelInfo(ctx->channel, chInfo);
     }
-    catch (sdbusplus::exception_t& e)
+    catch (const sdbusplus::exception_t& e)
     {
         return false;
     }