ANDROID: Fix up ipvlan merge in 5.10.202

In commit 43b781e7 ("ipvlan: add ipvlan_route_v6_outbound()
helper"), DEV_STATS_INC() is used, but that's not a valid api in the
5.10.y Android tree due to it breaking the abi.  So fix this up by hand
to use the "old-style" stats increment call to resolve the build issues.

Fixes: 43b781e7 ("ipvlan: add ipvlan_route_v6_outbound() helper")
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Id7bdb1b5f742ae32b7f9e8f6db808c5763a8394c