add exception catch-all in main

Catch all derived exceptions that may be thrown from the Updater.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I7ab1e74fc1378a3e8f73eae40295e42ef7a2833a
diff --git a/tools/main.cpp b/tools/main.cpp
index 640016a..5868d11 100644
--- a/tools/main.cpp
+++ b/tools/main.cpp
@@ -27,6 +27,7 @@
 
 #include <algorithm>
 #include <cstdio>
+#include <exception>
 #include <iostream>
 #include <ipmiblob/blob_handler.hpp>
 #include <ipmiblob/ipmi_handler.hpp>
@@ -182,6 +183,12 @@
             std::fprintf(stderr, "Exception received: %s\n", e.what());
             return -1;
         }
+        catch (const std::exception& e)
+        {
+            std::fprintf(stderr, "Unexpected exception received: %s\n",
+                         e.what());
+            return -1;
+        }
     }
 
     return 0;