don't bother with ->d_inode->i_sb - it's always equal to ->d_sb

... and neither can ever be NULL

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index 4e4b2fa7..09c71e9 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -872,7 +872,7 @@
 	TP_fast_assign(
 		struct dentry *dentry = file->f_path.dentry;
 
-		__entry->dev		= d_inode(dentry)->i_sb->s_dev;
+		__entry->dev		= dentry->d_sb->s_dev;
 		__entry->ino		= d_inode(dentry)->i_ino;
 		__entry->datasync	= datasync;
 		__entry->parent		= d_inode(dentry->d_parent)->i_ino;
@@ -1451,7 +1451,7 @@
 	),
 
 	TP_fast_assign(
-		__entry->dev		= d_inode(dentry)->i_sb->s_dev;
+		__entry->dev		= dentry->d_sb->s_dev;
 		__entry->ino		= d_inode(dentry)->i_ino;
 		__entry->parent		= parent->i_ino;
 		__entry->size		= d_inode(dentry)->i_size;
@@ -1475,7 +1475,7 @@
 	),
 
 	TP_fast_assign(
-		__entry->dev		= d_inode(dentry)->i_sb->s_dev;
+		__entry->dev		= dentry->d_sb->s_dev;
 		__entry->ino		= d_inode(dentry)->i_ino;
 		__entry->ret		= ret;
 	),