f2fs: lost matching-pair of trace in f2fs_truncate_inode_blocks

if get_node_path() return -E2BIG and trace of
f2fs_truncate_inode_blocks_enter/exit enabled
then the matching-pair of trace_exit will lost
in log.

Signed-off-by: Yubo Feng <fengyubo3@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>