syscall: delete the "use" function and calls in non-generated files.

Delete use stub from asm.s, leaving only a dummy file.
Deleting the file causes Windows build to fail.

Fixes #16607

Change-Id: Ic5a55e042e588f1e1bc6605a3d309d1eabdeb288
Reviewed-on: https://go-review.googlesource.com/36716
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/syscall/syscall_linux_arm.go

@@ -123,7 +123,6 @@ func Statfs(path string, buf *Statfs_t) (err error) {
 		return err
 	}
 	_, _, e := Syscall(SYS_STATFS64, uintptr(unsafe.Pointer(pathp)), unsafe.Sizeof(*buf), uintptr(unsafe.Pointer(buf)))
-	use(unsafe.Pointer(pathp))
 	if e != 0 {
 		err = e
 	}