Remove Platform.HasFileShares query

src/System.Management.Automation/CoreCLR/CorePsPlatform.cs

@@ -217,14 +217,6 @@ namespace System.Management.Automation
 
         }
 
-        // Linux has no notion of file shares. It has mount points
-        // instead, which are subdirectories of its single-root
-        // filesystem.
-        internal static bool HasFileShares()
-        {
-            return IsWindows();
-        }
-
         // Linux has no support for UNC, just mounts in a single rooted hierarchy
         // the UNC equivalent of a "network drive" aka mount would be the mount itself
         internal static bool HasUNCSupport()

src/System.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs

@@ -4464,12 +4464,9 @@ namespace System.Management.Automation
 
         internal static List<string> GetFileShares(string machine, bool ignoreHidden)
         {
-            // Platform notes: don't throw an exception since this is being used in auto-completion
-            if (!Platform.HasFileShares())
-            {
-                return new List<string>();
-            }
-
+#if LINUX
+            return new List<string>();
+#else
             IntPtr shBuf;
             uint numEntries;
             uint totalEntries;
@@ -4495,6 +4492,7 @@ namespace System.Management.Automation
                 }
             }
             return shares;
+#endif
         }
 
         private static bool CheckFileExtension(string path, HashSet<string> extension)