The seq_printf return value, because it's frequently misused,
will eventually be converted to void.
See: commit 
1f33c41c03da ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")
Miscellanea:
o Remove unused return value from trace_lookup_stack
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
        local_irq_enable();
 }
 
-static int trace_lookup_stack(struct seq_file *m, long i)
+static void trace_lookup_stack(struct seq_file *m, long i)
 {
        unsigned long addr = stack_dump_trace[i];
 
-       return seq_printf(m, "%pS\n", (void *)addr);
+       seq_printf(m, "%pS\n", (void *)addr);
 }
 
 static void print_disabled(struct seq_file *m)