os: omit existence check for GetFinalPathNameByHandle

GetFinalPathNameByHandle exists since Windows Vista, which we no longer
support, so we don't need to prove that it exists before using it.

Updates #57003

Change-Id: Iff2bbe51d3baa3aabcaacf39ea3cbeda0088b9d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/522195
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>

Author: qmuntal

src/internal/syscall/windows/syscall_windows.go

@@ -365,10 +365,6 @@ const (
 
 //sys	GetFinalPathNameByHandle(file syscall.Handle, filePath *uint16, filePathSize uint32, flags uint32) (n uint32, err error) = kernel32.GetFinalPathNameByHandleW
 
-func LoadGetFinalPathNameByHandle() error {
-	return procGetFinalPathNameByHandleW.Find()
-}
-
 func ErrorLoadingGetTempPath2() error {
 	return procGetTempPath2W.Find()
 }

src/os/file_windows.go

@@ -377,12 +377,6 @@ func normaliseLinkPath(path string) (string, error) {
 
 	// handle paths, like \??\Volume{abc}\...
 
-	err := windows.LoadGetFinalPathNameByHandle()
-	if err != nil {
-		// we must be using old version of Windows
-		return "", err
-	}
-
 	h, err := openSymlink(path)
 	if err != nil {
 		return "", err