vfs: make path_openat take a struct filename pointer

...and fix up the callers. For do_file_open_root, just declare a
struct filename on the stack and fill out the .name field. For
do_filp_open, make it also take a struct filename pointer, and fix up its
callers to call it appropriately.

For filp_open, add a variant that takes a struct filename pointer and turn
filp_open into a wrapper around it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/internal.h b/fs/internal.h
index 371bcc4..916b7cb 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -97,8 +97,8 @@
 	int acc_mode;
 	int intent;
 };
-extern struct file *do_filp_open(int dfd, const char *pathname,
-		const struct open_flags *op, int lookup_flags);
+extern struct file *do_filp_open(int dfd, struct filename *pathname,
+		const struct open_flags *op, int flags);
 extern struct file *do_file_open_root(struct dentry *, struct vfsmount *,
 		const char *, const struct open_flags *, int lookup_flags);