cache bypass: fix afs_bypass_copy_page memcpy oops

cache bypass: fix afs_bypass_copy_page memcpy oops

The two memory copy cases were inverted when the code was
refactored, causing an oops when cache bypass is enabled.

Reviewed-on: http://gerrit.openafs.org/8617
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Tested-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
(cherry picked from commit 5b2cc290f8e991b152411168cabd1c9e7f31deb4)

Change-Id: Ia5eb577046895a2b38a6be5c4794db9a65893530
Reviewed-on: http://gerrit.openafs.org/8715
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Tested-by: Stephan Wiesand <stephan.wiesand@desy.de>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Paul Smeddle <paul.smeddle@gmail.com>