[llvm] [llvm-objcopy] Improve help messages (PR #82830)

[James Henderson via llvm-commits]

================
@@ -484,7 +484,7 @@ them.
 
 .. option:: --weaken-symbol <symbol>, -W
 
- Mark any global symbol named ``<symbol>`` as a weak symbol in the output. Can
+ Mark global symbols named ``<symbol>`` as a weak symbol in the output. Can
----------------
jh7370 wrote:

```suggestion
 Mark global symbols named ``<symbol>`` as weak symbols in the output. Can
```
Need to use plurals in both places.

https://github.com/llvm/llvm-project/pull/82830