vsprintf: avoid misleading "(null)" for %px

Like %pK already does, print "00000000" instead.

This confused people -- the convention is that "(null)" means you tried to
dereference a null pointer as opposed to printing the address.

Link: http://lkml.kernel.org/r/[email protected]
To: Sergey Senozhatsky <[email protected]>
To: Steven Rostedt <[email protected]>
To: [email protected]
Cc: Andrew Morton <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: "Roberts, William C" <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: David Laight <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Signed-off-by: Adam Borowski <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>

Author: kilobyte

lib/vsprintf.c

@@ -1849,7 +1849,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 {
 	const int default_width = 2 * sizeof(void *);
 
-	if (!ptr && *fmt != 'K') {
+	if (!ptr && *fmt != 'K' && *fmt != 'x') {
 		/*
 		 * Print (null) with the same width as a pointer so it makes
 		 * tabular output look nice.