docs: move botching-up-ioctls.rst to the process guide

This is overall information for kernel developers, and not part of the
user-space API.

Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/ioctl/index.rst

@@ -9,7 +9,6 @@ IOCTLs
 
    ioctl-number
 
-   botching-up-ioctls
    ioctl-decoding
 
    cdrom

Documentation/process/index.rst

@@ -58,6 +58,7 @@ lack of a better place.
    adding-syscalls
    magic-number
    volatile-considered-harmful
+   botching-up-ioctls
    clang-format
 
 .. only::  subproject and html