Revert "xfrm: interface: use DEV_STATS_INC()"

This reverts commit 4ba4eec4 which is
commit f7c4e3e5 upstream.

It breaks the build as it relies on a reverted patch.  if it is needed
for this branch, it can come back in an abi-safe way.

Change-Id: I18ecdab21ea8a95132d62abac9c189e8589c16b0
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>