Revert "debugfs: more tightly restrict default mount mode"

This reverts commit 82aceae4f0.

The wlan module makes some debugfs directories when it is loaded.
Android userspace loads the wlan module as the system user and
the system user doesn't have write access to the debugfs
filesystem because the default permissions for debugfs are 0700
now. Revert this patch to allow the wlan module to create
directories in debugfs and successfully probe.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Documentation/filesystems/debugfs.txt

@@ -15,8 +15,8 @@ Debugfs is typically mounted with a command like:
     mount -t debugfs none /sys/kernel/debug
 
 (Or an equivalent /etc/fstab line).
-The debugfs root directory is accessible only to the root user by
-default. To change access to the tree the "uid", "gid" and "mode" mount
+The debugfs root directory is accessible by anyone by default. To
+restrict access to the tree the "uid", "gid" and "mode" mount
 options can be used.
 
 Note that the debugfs API is exported GPL-only to modules.

fs/debugfs/inode.c

@@ -28,7 +28,7 @@
 #include <linux/magic.h>
 #include <linux/slab.h>
 
-#define DEBUGFS_DEFAULT_MODE	0700
+#define DEBUGFS_DEFAULT_MODE	0755
 
 static struct vfsmount *debugfs_mount;
 static int debugfs_mount_count;