jbd2: avoid -Wempty-body warnings

Building with 'make W=1' shows a harmless -Wempty-body warning:

fs/jbd2/recovery.c: In function 'fc_do_one_pass':
fs/jbd2/recovery.c:267:75: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
  267 |                 jbd_debug(3, "Fast commit replay failed, err = %d\n", err);
      |                                                                           ^

Change the empty dprintk() macros to no_printk(), which avoids this
warning and adds format string checking.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210322102152.95684-1-arnd@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

include/linux/jbd2.h

@@ -61,7 +61,7 @@ void __jbd2_debug(int level, const char *file, const char *func,
 #define jbd_debug(n, fmt, a...) \
 	__jbd2_debug((n), __FILE__, __func__, __LINE__, (fmt), ##a)
 #else
-#define jbd_debug(n, fmt, a...)    /**/
+#define jbd_debug(n, fmt, a...)  no_printk(fmt, ##a)
 #endif
 
 extern void *jbd2_alloc(size_t size, gfp_t flags);