printk: fix wrong format string iter for printk

printk("%Q");

 Output before patch:  %QQ
 Output  after patch:  %Q
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: torvalds@linux-foundation.org
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49CC97B6.7040809@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

lib/vsprintf.c

@@ -1051,13 +1051,6 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 			if (str < end)
 				*str = '%';
 			++str;
-			if (*fmt) {
-				if (str < end)
-					*str = *fmt;
-				++str;
-			} else {
-				--fmt;
-			}
 			break;
 
 		case FORMAT_TYPE_NRCHARS: {
@@ -1339,8 +1332,6 @@ do {									\
 			break;
 
 		case FORMAT_TYPE_INVALID:
-			if (!*fmt)
-				--fmt;
 			break;
 
 		case FORMAT_TYPE_NRCHARS: {
@@ -1523,13 +1514,6 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 			if (str < end)
 				*str = '%';
 			++str;
-			if (*fmt) {
-				if (str < end)
-					*str = *fmt;
-				++str;
-			} else {
-				--fmt;
-			}
 			break;
 
 		case FORMAT_TYPE_NRCHARS: