arm: uaccess: Remove memcpy_page_flushcache()

Commit 21b56c84 ("iov_iter: get rid of separate bvec and xarray
callbacks") removed the calls to memcpy_page_flushcache().

Remove the unnecessary memcpy_page_flushcache() call.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Dan Williams" <dan.j.williams@intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20221230-kmap-x86-v1-3-15f1ecccab50@intel.com


Signed-off-by: Will Deacon <will@kernel.org>