[LLD] [ELF] Fix up a comment regarding the --wrap option. NFC.

Add missing leading underscores to the __wrap_<symbol> and
__real_<symbol> names.

Differential Revision: https://reviews.llvm.org/D89008

lld/ELF/Driver.cpp

@@ -1837,9 +1837,9 @@ template <class ELFT> void LinkerDriver::compileBitcodeFiles() {
 
 // The --wrap option is a feature to rename symbols so that you can write
 // wrappers for existing functions. If you pass `-wrap=foo`, all
-// occurrences of symbol `foo` are resolved to `wrap_foo` (so, you are
-// expected to write `wrap_foo` function as a wrapper). The original
-// symbol becomes accessible as `real_foo`, so you can call that from your
+// occurrences of symbol `foo` are resolved to `__wrap_foo` (so, you are
+// expected to write `__wrap_foo` function as a wrapper). The original
+// symbol becomes accessible as `__real_foo`, so you can call that from your
 // wrapper.
 //
 // This data structure is instantiated for each -wrap option.