nilfs2: delete unnecessary checks before brelse()

nilfs2: delete unnecessary checks before brelse()

Patch series "nilfs2 minor amendments".

This patch (of 2):

The brelse() inline function tests whether its argument is NULL and then
returns immediately.  Thus remove the tests which are not needed around
the shown calls.

Link: https://lkml.kernel.org/r/20220921034803.2476-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20220819081700.96279-1-chi.minghao@zte.com.cn
Link: https://lkml.kernel.org/r/20220921034803.2476-2-konishi.ryusuke@gmail.com
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: ye xingchen <ye.xingchen@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>