[LLD] [COFF] Fix option name references in Config.h. NFC.

These options have been named /lldltocache: and
/lldltocachepolicy: since they were added in
052e855; the comment was
wrong from the original commit.

Author: mstorsjo

lld/COFF/Config.h

@@ -186,9 +186,9 @@ struct Configuration {
   // Used for /opt:lldltopartitions=N
   unsigned ltoPartitions = 1;
 
-  // Used for /opt:lldltocache=path
+  // Used for /lldltocache=path
   StringRef ltoCache;
-  // Used for /opt:lldltocachepolicy=policy
+  // Used for /lldltocachepolicy=policy
   llvm::CachePruningPolicy ltoCachePolicy;
 
   // Used for /opt:[no]ltodebugpassmanager