io: Remove copy_file_range emulation [BZ #24744]

io: Remove copy_file_range emulation [BZ #24744]

The kernel is evolving this interface (e.g., removal of the
restriction on cross-device copies), and keeping up with that
is difficult.  Applications which need the function should
run kernels which support the system call instead of relying on
the imperfect glibc emulation.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 5a659ccc0ec217ab02a4c273a1f6d346a359560a)