UBIFS: Align the dump messages of SB_NODE

I found the dump messages of UBIFS_SB_NODE is not aligned. This
patch remove the extra space from the line which is retracted.

Signed-off-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>