mm: remove_memory(): fix end_pfn setting

remove_memory() calls walk_memory_range() with [start_pfn, end_pfn), where
end_pfn is exclusive in this range.  Therefore, end_pfn needs to be set to
the next page of the end address.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/fremap.c: fix oops on error path

If find_vma() fails, sys_remap_file_pages() will dereference `vma', which
contains NULL.  Fix it by checking the pointer.

(We could alternatively check for err==0, but this seems more direct)

(The vm_flags change is to squish a bogus used-uninitialised warning
without adding extra code).

Reported-by: Tommi Rantala <tt.rantala@gmail.com>
Cc: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>