nilfs2: use a more common logging style

Add macros for nilfs_<level>(sb, fmt, ...) and convert the uses of
'nilfs_msg(sb, KERN_<LEVEL>, ...)' to 'nilfs_<level>(sb, ...)' so nilfs2
uses a logging style more like the typical kernel logging style.

Miscellanea:

o Realign arguments for these uses

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1595860111-3920-4-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nilfs2/gcinode.c

@@ -142,7 +142,7 @@ int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *bh)
 	if (!buffer_uptodate(bh)) {
 		struct inode *inode = bh->b_page->mapping->host;
 
-		nilfs_msg(inode->i_sb, KERN_ERR,
+		nilfs_err(inode->i_sb,
 			  "I/O error reading %s block for GC (ino=%lu, vblocknr=%llu)",
 			  buffer_nilfs_node(bh) ? "node" : "data",
 			  inode->i_ino, (unsigned long long)bh->b_blocknr);