cmMakefile: Remove useless link directory container

It is never populated - a find will never find anything.

Source/cmMakefile.cxx

@@ -1857,10 +1857,7 @@ void cmMakefile::AddGlobalLinkInformation(const std::string& name,
       if (*j->rbegin() == '/') {
         newdir = j->substr(0, j->size() - 1);
       }
-      if (std::find(this->LinkDirectories.begin(), this->LinkDirectories.end(),
-                    newdir) == this->LinkDirectories.end()) {
-        target.AddLinkDirectory(*j);
-      }
+      target.AddLinkDirectory(*j);
     }
   }
 

Source/cmMakefile.h

@@ -805,9 +805,6 @@ protected:
   // Tests
   std::map<std::string, cmTest*> Tests;
 
-  // The link-library paths.  Order matters, use std::vector (not std::set).
-  std::vector<std::string> LinkDirectories;
-
   // The set of include directories that are marked as system include
   // directories.
   std::set<std::string> SystemIncludeDirectories;