[Linker] Update linkInModule() comment following change from bool OverrideSymbols to unsigned Flags (llvm#138531)

Original change:
llvm@020d4fb.

Author: bricknerb

llvm/include/llvm/Linker/Linker.h

@@ -25,6 +25,7 @@ class Linker {
 public:
   enum Flags {
     None = 0,
+    /// Have symbols from Src shadow those in the Dest.
     OverrideFromSrc = (1 << 0),
     LinkOnlyNeeded = (1 << 1),
   };
@@ -33,9 +34,6 @@ class Linker {
 
   /// Link \p Src into the composite.
   ///
-  /// Passing OverrideSymbols as true will have symbols from Src
-  /// shadow those in the Dest.
-  ///
   /// Passing InternalizeCallback will have the linker call the function with
   /// the new module and a list of global value names to be internalized by the
   /// callback.