Remove unused exception parameter from xplat/e2ee/gecko-serializer/V1…

…LlvSerializer.cpp

Summary:
`-Wunused-exception-parameter` has identified an unused exception parameter. This diff removes it.

This:
```
try {
    ...
} catch (exception& e) {
    // no use of e
}
```
should instead be written as
```
} catch (exception&) {
```

If the code compiles, this is safe to land.

Reviewed By: dmm-fb

Differential Revision: D60516159

fbshipit-source-id: 5e2b2f36975a47ff244ec9884d4237cf37c055dc

API/hermes/cdp/RemoteObjectConverters.cpp

@@ -81,7 +81,7 @@ static m::runtime::ObjectPreview generateArrayPreview(
     try {
       desc = generatePropertyPreview(
           runtime, indexString, obj.getValueAtIndex(runtime, i));
-    } catch (const jsi::JSError &err) {
+    } catch (const jsi::JSError &) {
       desc.name = indexString;
       desc.type = "string";
       desc.value = "<Exception>";
@@ -120,7 +120,7 @@ static m::runtime::ObjectPreview generateObjectPreview(
       // Chrome instead detects getters and makes you click to invoke.
       desc = generatePropertyPreview(
           runtime, propName.utf8(runtime), obj.getProperty(runtime, propName));
-    } catch (const jsi::JSError &err) {
+    } catch (const jsi::JSError &) {
       desc.name = propName.utf8(runtime);
       desc.type = "string";
       desc.value = "<Exception>";