[PATCH] sysctl: add register_sysctl() dummy helper

[Arnd Bergmann]

The register_sysctl() function has been around for five years with commit
fea478d4101a ("sysctl: Add register_sysctl for normal sysctl users")
but now that arm64 started using it, I ran into a compile error:

arch/arm64/kernel/armv8_deprecated.c: In function 'register_insn_emulation_sysctl':
arch/arm64/kernel/armv8_deprecated.c:257:2: error: implicit declaration of function 'register_sysctl'

This adds a inline function like we already have for register_sysctl_paths()
and register_sysctl_table().

Fixes: 38b9aeb32fa7 ("arm64: Port deprecated instruction emulation to new sysctl interface")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
This should probably get merged through the arm64 tree to avoid
bisection problems.
---
 include/linux/sysctl.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index fabe15e51c56..992bc9948232 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -216,6 +216,11 @@ static inline struct ctl_table_header *register_sysctl_paths(
 	return NULL;
 }
 
+static inline struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table)
+{
+	return NULL;
+}
+
 static inline void unregister_sysctl_table(struct ctl_table_header * table)
 {
 }
-- 
2.9.0