net: Don't forget pr_fmt on net_dbg_ratelimited for CONFIG_DYNAMIC_DEBUG

BugLink: http://bugs.launchpad.net/bugs/1601952

[ Upstream commit daddef76 ]

The implementation of net_dbg_ratelimited in the CONFIG_DYNAMIC_DEBUG
case was added with 2c94b537 ("net: Implement net_dbg_ratelimited() for
CONFIG_DYNAMIC_DEBUG case"). The implementation strategy was to take the
usual definition of the dynamic_pr_debug macro, but alter it by adding a
call to "net_ratelimit()" in the if statement. This is, in fact, the
correct approach.

However, while doing this, the author of the commit forgot to surround
fmt by pr_fmt, resulting in unprefixed log messages appearing in the
console. So, this commit adds back the pr_fmt(fmt) invocation, making
net_dbg_ratelimited properly consistent across DEBUG, no DEBUG, and
DYNAMIC_DEBUG cases, and bringing parity with the behavior of
dynamic_pr_debug as well.

Fixes: 2c94b537 ("net: Implement net_dbg_ratelimited() for CONFIG_DYNAMIC_DEBUG case")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Tim Bingham <tbingham@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

include/linux/net.h

@@ -251,7 +251,8 @@ do {									\
 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
 	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
 	    net_ratelimit())						\
-		__dynamic_pr_debug(&descriptor, fmt, ##__VA_ARGS__);	\
+		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),		\
+		                   ##__VA_ARGS__);			\
 } while (0)
 #elif defined(DEBUG)
 #define net_dbg_ratelimited(fmt, ...)				\