switch xattr_handler->set() to passing dentry and inode separately

preparation for similar switch in ->setxattr() (see the next commit for
rationale).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 00ea567..e3decae 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -50,10 +50,11 @@
 }
 
 static int f2fs_xattr_generic_set(const struct xattr_handler *handler,
-		struct dentry *dentry, const char *name, const void *value,
+		struct dentry *unused, struct inode *inode,
+		const char *name, const void *value,
 		size_t size, int flags)
 {
-	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 
 	switch (handler->flags) {
 	case F2FS_XATTR_INDEX_USER:
@@ -69,7 +70,7 @@
 	default:
 		return -EINVAL;
 	}
-	return f2fs_setxattr(d_inode(dentry), handler->flags, name,
+	return f2fs_setxattr(inode, handler->flags, name,
 					value, size, NULL, flags);
 }
 
@@ -95,11 +96,10 @@
 }
 
 static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
-		struct dentry *dentry, const char *name, const void *value,
+		struct dentry *unused, struct inode *inode,
+		const char *name, const void *value,
 		size_t size, int flags)
 {
-	struct inode *inode = d_inode(dentry);
-
 	if (!inode_owner_or_capable(inode))
 		return -EPERM;
 	if (value == NULL)