docs: Get module_init() docs from module.h

The docs build complains:

    ./include/linux/init.h:1: warning: no structured comments found

The problem is that the comments in question were moved to module.h in
commit 0fd972a7d91d (module: relocate module_init from init.h to
module.h).  Fix basics.rst to match.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/driver-api/basics.rst b/Documentation/driver-api/basics.rst
index ab82250..cbfb5a8 100644
--- a/Documentation/driver-api/basics.rst
+++ b/Documentation/driver-api/basics.rst
@@ -4,7 +4,7 @@
 Driver Entry and Exit points
 ----------------------------
 
-.. kernel-doc:: include/linux/init.h
+.. kernel-doc:: include/linux/module.h
    :internal:
 
 Driver device table