intel_th: msu: Fix possible memory leak in mode_store()

'mode' is malloced in mode_store() and should be freed before leaving
from the error handling cases, otherwise it will cause memory leak.

Fixes: 615c164 ("intel_th: msu: Introduce buffer interface")
Signed-off-by: Wei Yongjun <[email protected]>
Signed-off-by: Alexander Shishkin <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Wei Yongjun

drivers/hwtracing/intel_th/msu.c

@@ -1852,8 +1852,10 @@ mode_store(struct device *dev, struct device_attribute *attr, const char *buf,
 		return -ENOMEM;
 
 	i = match_string(msc_mode, ARRAY_SIZE(msc_mode), mode);
-	if (i >= 0)
+	if (i >= 0) {
+		kfree(mode);
 		goto found;
+	}
 
 	/* Buffer sinks only work with a usable IRQ */
 	if (!msc->do_irq) {