nilfs2: delete unnecessary condition in nilfs_dat_translate

This is a trivial patch to delete unnecessary condition in nilfs_dat_translate.

nilfs_dat_translate() will asign translated address to *blocknrp if blocknrp
is not NULL.  However the condition is unneeded, because all callers of
nilfs_dat_translate() pass blocknrp properly.
Signed-off-by: NJiro SEKIBA <jir@unicus.jp>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

fs/nilfs2/dat.c

@@ -388,8 +388,7 @@ int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
 		ret = -ENOENT;
 		goto out;
 	}
-	if (blocknrp != NULL)
-		*blocknrp = blocknr;
+	*blocknrp = blocknr;
 
  out:
 	kunmap_atomic(kaddr, KM_USER0);