seq_buf: Mark binary printing functions with __printf() attribute

Binary printing functions are using printf() type of format, and compiler
is not happy about them as is:

lib/seq_buf.c:162:17: error: function ‘seq_buf_bprintf’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format]

Fix the compilation errors by adding __printf() attribute.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>

Author: andy-shev

include/linux/seq_buf.h

@@ -167,8 +167,8 @@ extern int seq_buf_hex_dump(struct seq_buf *s, const char *prefix_str,
 			    const void *buf, size_t len, bool ascii);
 
 #ifdef CONFIG_BINARY_PRINTF
-extern int
-seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary);
+__printf(2, 0)
+int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary);
 #endif
 
 void seq_buf_do_printk(struct seq_buf *s, const char *lvl);