d_path: Make d_path() use a struct path

d_path() is used on a <dentry,vfsmount> pair.  Lets use a struct path to
reflect this.

[akpm@linux-foundation.org: fix build in mm/memory.c]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Bryan Wu <bryan.wu@analog.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index ee32c0e..c6e72ae 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -2853,7 +2853,7 @@
 	/* find the name of the device. */
 	path = (char *)__get_free_page(GFP_KERNEL);
 	if (path) {
-		fn = d_path(filp->f_path.dentry, filp->f_path.mnt, path, PAGE_SIZE);
+		fn = d_path(&filp->f_path, path, PAGE_SIZE);
 		if (IS_ERR(fn))
 			fn = "?";
 	}