dynamic_debug: make dynamic-debug supersede DEBUG ccflag

If CONFIG_DYNAMIC_DEBUG is defined, honor it over DEBUG, so that
pr_debug()s are controllable, instead of always-on.  When DEBUG is
also defined, change _DPRINTK_FLAGS_DEFAULT to enable printing by
default.

Also adding _DPRINTK_FLAGS_INCL_MODNAME would be nice, but there are
numerous cases of pr_debug(NAME ": ...), which would result in double
printing of module-name.  So defer this until things settle.

Cc: David Miller <davem@davemloft.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/printk.h b/include/linux/printk.h
index f0e22f7..f9abd93 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -180,13 +180,13 @@
 #endif
 
 /* If you are writing a driver, please use dev_dbg instead */
-#if defined(DEBUG)
-#define pr_debug(fmt, ...) \
-	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
-#elif defined(CONFIG_DYNAMIC_DEBUG)
+#if defined(CONFIG_DYNAMIC_DEBUG)
 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
 #define pr_debug(fmt, ...) \
 	dynamic_pr_debug(fmt, ##__VA_ARGS__)
+#elif defined(DEBUG)
+#define pr_debug(fmt, ...) \
+	printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 #else
 #define pr_debug(fmt, ...) \
 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)