[PATCH] doc: add kernel-doc comment for u64_to_user_ptr

[Federico Vaga]

Add a kernel-doc comment in kernel.h to document the macro
`u64_to_user_ptr`.

As of today, this macro is mentioned in the documentation in
'ioctl.rst' and 'botching-up-ioctls.rst'

Signed-off-by: Federico Vaga <federico.vaga@xxxxxxxxxx>
---
 include/linux/kernel.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index fe6efb24d151..8bcd126f64f2 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -56,6 +56,10 @@
 
 #define PTR_IF(cond, ptr)	((cond) ? (ptr) : NULL)
 
+/**
+ * u64_to_user_ptr - convert an unsigned 64bit number into a user pointer
+ * @x: the number to convert
+ */
 #define u64_to_user_ptr(x) (		\
 {					\
 	typecheck(u64, (x));		\
-- 
2.30.2