pwm: Add missing newline

checkpatch requires that declarations be separated from code by a blank
line. Add one for readability and to silence the warning.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 7831bc6..bc0c20ac 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -75,6 +75,7 @@
 
 	for (i = 0; i < chip->npwm; i++) {
 		struct pwm_device *pwm = &chip->pwms[i];
+
 		radix_tree_delete(&pwm_tree, pwm->pwm);
 	}