Revert "nvmem: core: fix return value"

This reverts commit e9538103 which is
commit 0c4862b1 upstream.

It breaks the Android kernel api, and isn't even really needed in the
5.10.y kernel tree yet, as there are no users of the new field.  So
revert it for now.  If it is needed, it can be brought back in an
abi-safe way in the future.

Bug: 161946584
Change-Id: I4e335c73a46ba291c790e54f40350a754ff6376b
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>