[PATCH v2 3/3] sunrpc: Fix compilation error (`make W=1`) when dprintk() is no-op

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

Clang compiler is not happy about set but unused variables:

.../flexfilelayout/flexfilelayoutdev.c:56:9: error: variable 'ret' set but not used [-Werror,-Wunused-but-set-variable]
.../flexfilelayout/flexfilelayout.c:1505:6: error: variable 'err' set but not used [-Werror,-Wunused-but-set-variable]
.../nfs4proc.c:9244:12: error: variable 'ptr' set but not used [-Werror,-Wunused-but-set-variable]

Fix these by forwarding parameters of dprintk() to no_printk().
The positive side-effect is a format-string checker enabled even for the cases
when dprintk() is no-op.

Fixes: d67ae825a59d ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Fixes: fc931582c260 ("nfs41: create_session operation")
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 fs/lockd/svclock.c           | 5 +++++
 include/linux/sunrpc/debug.h | 8 ++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index 712df1e025d8..dcd3e0b4d997 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -80,6 +80,11 @@ static const char *nlmdbg_cookie2a(const struct nlm_cookie *cookie)
 
 	return buf;
 }
+#else
+static inline const char *nlmdbg_cookie2a(const struct nlm_cookie *cookie)
+{
+	return "???";
+}
 #endif
 
 /*
diff --git a/include/linux/sunrpc/debug.h b/include/linux/sunrpc/debug.h
index e947d668f7b7..82239d5c262e 100644
--- a/include/linux/sunrpc/debug.h
+++ b/include/linux/sunrpc/debug.h
@@ -40,6 +40,8 @@ extern unsigned int		nlm_debug;
 do {									\
 	ifdebug(fac)							\
 		__sunrpc_printk(fmt, ##__VA_ARGS__);			\
+	else								\
+		no_printk(fmt, ##__VA_ARGS__);				\
 } while (0)
 
 # define dfprintk_rcu(fac, fmt, ...)					\
@@ -48,13 +50,15 @@ do {									\
 		rcu_read_lock();					\
 		__sunrpc_printk(fmt, ##__VA_ARGS__);			\
 		rcu_read_unlock();					\
+	} else {							\
+		no_printk(fmt, ##__VA_ARGS__);				\
 	}								\
 } while (0)
 
 #else
 # define ifdebug(fac)		if (0)
-# define dfprintk(fac, fmt, ...)	do {} while (0)
-# define dfprintk_rcu(fac, fmt, ...)	do {} while (0)
+# define dfprintk(fac, fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+# define dfprintk_rcu(fac, fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
 #endif
 
 /*
-- 
2.50.1