closures: use seq_putc() in debug_show()

A single line break should be put into a sequence. Thus use the
corresponding function "seq_putc".

This issue was transformed by using the Coccinelle software.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Markus Elfring <[e-mail]>
Cc: Kent Overstreet <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

lib/closure.c

···
 			seq_printf(f, " W %pS\n",
 				   (void *) cl->waiting_on);
 
-		seq_puts(f, "\n");
+		seq_putc(f, '\n');
 	}
 
 	spin_unlock_irq(&closure_list_lock);