nilfs2: remove individual gfp constants for each metadata file

This gets rid of NILFS_CPFILE_GFP, NILFS_SUFILE_GFP, NILFS_DAT_GFP,
and NILFS_IFILE_GFP.  All of these constants refer to NILFS_MDT_GFP,
and can be removed.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c
index 1ae8d56..9cb8318 100644
--- a/fs/nilfs2/mdt.c
+++ b/fs/nilfs2/mdt.c
@@ -513,9 +513,10 @@
 }
 
 struct inode *nilfs_mdt_new(struct the_nilfs *nilfs, struct super_block *sb,
-			    ino_t ino, gfp_t gfp_mask)
+			    ino_t ino)
 {
-	struct inode *inode = nilfs_mdt_new_common(nilfs, sb, ino, gfp_mask);
+	struct inode *inode = nilfs_mdt_new_common(nilfs, sb, ino,
+						   NILFS_MDT_GFP);
 
 	if (!inode)
 		return NULL;