power: msm-core: Fix mutex not getting unlocked in error path

When this copy_to_user() fails, the mutex won't be unlocked. Fix it.

Change-Id: I99c93fd04e812d187b83ff375d95a2abba82f501
Signed-off-by: Sultanxda <sultanxda@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/power/qcom/msm-core.c

@@ -521,7 +521,7 @@ static long msm_core_ioctl(struct file *file, unsigned int cmd,
 				node->sp->voltage,
 				sizeof(uint32_t) * node->sp->num_of_freqs);
 		if (ret)
-			break;
+			goto unlock;
 		for (i = 0; i < node->sp->num_of_freqs; i++) {
 			ret = copy_to_user((void __user *)&argp->freq[i],
 					&node->sp->table[i].frequency,