cgroups: Fix compile time error

Fix this prototype mismatch error.

==
mm/memcontrol.c:2264:6: error: conflicting types for
'mem_cgroup_end_page_stat'
void mem_cgroup_end_page_stat(struct mem_cgroup *memcg, bool *locked,

In file included from mm/memcontrol.c:29:0:
include/linux/memcontrol.h:144:6: note: previous declaration of
'mem_cgroup_end_page_stat' was here
void mem_cgroup_end_page_stat(struct mem_cgroup *memcg, bool *locked,
==

CRs-Fixed: 988758
Change-Id: Ic996cff7ccd5c2487bc76184922da012e70265ba
Signed-off-by: Kishore Srivenkata Ganesh Bolisetty <bsrivenk@codeaurora.org>
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>