coresight: tmc: Remove duplicate memset

The tmc_etr_enable_hw() fills the buffer with 0's before enabling
the hardware. So, we don't need an explicit memset() in
tmc_enable_etr_sink_sysfs() before calling the tmc_etr_enable_hw().
This patch removes the explicit memset from tmc_enable_etr_sink_sysfs.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-tmc-etr.c

@@ -150,8 +150,6 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
 		drvdata->buf = drvdata->vaddr;
 	}
 
-	memset(drvdata->vaddr, 0, drvdata->size);
-
 	drvdata->mode = CS_MODE_SYSFS;
 	tmc_etr_enable_hw(drvdata);
 out: