[RESEND PATCH] drbd: avoid clang warning about unmatched switch statement

[Arnd Bergmann]

The drbd code causes warnings that we cannot easily disable when building with clang:

In file included from drivers/block/drbd/drbd_debugfs.c:10:
In file included from drivers/block/drbd/drbd_int.h:48:
In file included from include/linux/drbd_genl_api.h:53:
In file included from include/linux/genl_magic_struct.h:237:
include/linux/drbd_genl.h:300:1: warning: no case matching constant switch condition '0'

There is nothing wrong with the code, and adding 'default:' labels
in the right place is enough to let clang shut up about the warning.

Fixes: ec2c35ac1ea2 ("drbd: prepare the transition from connector to genetlink")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Acked-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
---
Originally submitted on Feb 1, but not yet merged into v4.11-rc2
---
 include/linux/genl_magic_struct.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/linux/genl_magic_struct.h b/include/linux/genl_magic_struct.h
index 6270a56e5edc..c6fbafb834f1 100644
--- a/include/linux/genl_magic_struct.h
+++ b/include/linux/genl_magic_struct.h
@@ -190,6 +190,7 @@ static inline void ct_assert_unique_operations(void)
 {
 	switch (0) {
 #include GENL_MAGIC_INCLUDE_FILE
+	default:
 		;
 	}
 }
@@ -208,6 +209,7 @@ static inline void ct_assert_unique_top_level_attributes(void)
 {
 	switch (0) {
 #include GENL_MAGIC_INCLUDE_FILE
+	default:
 		;
 	}
 }
@@ -218,6 +220,7 @@ static inline void ct_assert_unique_ ## s_name ## _attributes(void)	\
 {									\
 	switch (0) {							\
 		s_fields						\
+		default:						\
 			;						\
 	}								\
 }
-- 
2.9.0