catch exceptions as const

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I6a2316d11f1dd70d8dc2368c2aa01d88cf1cdb26
diff --git a/oem/ibm/libpldmresponder/file_io.cpp b/oem/ibm/libpldmresponder/file_io.cpp
index 1192510..7d46a38 100644
--- a/oem/ibm/libpldmresponder/file_io.cpp
+++ b/oem/ibm/libpldmresponder/file_io.cpp
@@ -262,7 +262,7 @@
     {
         value = table.at(fileHandle);
     }
-    catch (std::exception& e)
+    catch (const std::exception& e)
     {
         std::cerr << "File handle does not exist in the file table, HANDLE="
                   << fileHandle << "\n";
@@ -354,7 +354,7 @@
     {
         value = table.at(fileHandle);
     }
-    catch (std::exception& e)
+    catch (const std::exception& e)
     {
         std::cerr << "File handle does not exist in the file table, HANDLE="
                   << fileHandle << "\n";
@@ -479,7 +479,7 @@
     {
         value = table.at(fileHandle);
     }
-    catch (std::exception& e)
+    catch (const std::exception& e)
     {
         std::cerr << "File handle does not exist in the file table, HANDLE="
                   << fileHandle << "\n";
@@ -560,7 +560,7 @@
     {
         value = table.at(fileHandle);
     }
-    catch (std::exception& e)
+    catch (const std::exception& e)
     {
         std::cerr << "File handle does not exist in the file table, HANDLE="
                   << fileHandle << "\n";