f2fs: fix wrong condition to trigger background checkpoint correctly

f2fs: fix wrong condition to trigger background checkpoint correctly

[ Upstream commit cd6d697a6e2013a0a85f8b261b16c8cfd50c1f5f ]

In f2fs_balance_fs_bg(), it needs to check both NAT_ENTRIES and INO_ENTRIES
memory usage to decide whether we should skip background checkpoint, otherwise
we may always skip checking INO_ENTRIES memory usage, so that INO_ENTRIES may
potentially cause high memory footprint.

Fixes: 493720a48543 ("f2fs: fix to avoid REQ_TIME and CP_TIME collision")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>