pwm: use seq_puts() instead of seq_printf()

For a constant format without additional arguments, use seq_puts()
instead of seq_printf(). Also, the following checkpatch warning is
fixed.

  WARNING: Prefer seq_puts to seq_printf
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/core.c

@@ -808,12 +808,12 @@ static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
 		seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
 
 		if (test_bit(PWMF_REQUESTED, &pwm->flags))
-			seq_printf(s, " requested");
+			seq_puts(s, " requested");
 
 		if (test_bit(PWMF_ENABLED, &pwm->flags))
-			seq_printf(s, " enabled");
+			seq_puts(s, " enabled");
 
-		seq_printf(s, "\n");
+		seq_puts(s, "\n");
 	}
 }