Merge tag 'docs-4.12' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "A reasonably busy cycle for documentation this time around. There is a
  new guide for user-space API documents, rather sparsely populated at
  the moment, but it's a start. Markus improved the infrastructure for
  converting diagrams. Mauro has converted much of the USB documentation
  over to RST. Plus the usual set of fixes, improvements, and tweaks.

  There's a bit more than the usual amount of reaching out of
  Documentation/ to fix comments elsewhere in the tree; I have acks for
  those where I could get them"

* tag 'docs-4.12' of git://git.lwn.net/linux: (74 commits)
  docs: Fix a couple typos
  docs: Fix a spelling error in vfio-mediated-device.txt
  docs: Fix a spelling error in ioctl-number.txt
  MAINTAINERS: update file entry for HSI subsystem
  Documentation: allow installing man pages to a user defined directory
  Doc/PM: Sync with intel_powerclamp code behavior
  zr364xx.rst: usb/devices is now at /sys/kernel/debug/
  usb.rst: move documentation from proc_usb_info.txt to USB ReST book
  convert philips.txt to ReST and add to media docs
  docs-rst: usb: update old usbfs-related documentation
  arm: Documentation: update a path name
  docs: process/4.Coding.rst: Fix a couple of document refs
  docs-rst: fix usb cross-references
  usb: gadget.h: be consistent at kernel doc macros
  usb: composite.h: fix two warnings when building docs
  usb: get rid of some ReST doc build errors
  usb.rst: get rid of some Sphinx errors
  usb/URB.txt: convert to ReST and update it
  usb/persist.txt: convert to ReST and add to driver-api book
  usb/hotplug.txt: convert to ReST and add to driver-api book
  ...

drivers/usb/core/Kconfig

@@ -26,7 +26,7 @@ config USB_DEFAULT_PERSIST
 	  unplugged, causing any mounted filesystems to be lost.  The
 	  persist feature can still be enabled for individual devices
 	  through the power/persist sysfs node. See
-	  Documentation/usb/persist.txt for more info.
+	  Documentation/driver-api/usb/persist.rst for more info.
 
 	  If you have any questions about this, say Y here, only say N
 	  if you know exactly what you are doing.

drivers/usb/core/message.c

@@ -474,6 +474,7 @@ EXPORT_SYMBOL_GPL(usb_sg_init);
  * significantly improve USB throughput.
  *
  * There are three kinds of completion for this function.
+ *
  * (1) success, where io->status is zero.  The number of io->bytes
  *     transferred is as requested.
  * (2) error, where io->status is a negative errno value.  The number