amdgpu: securedisplay: simplify i2c hexdump output

A previous fix I did left a rather complicated loop in
amdgpu_securedisplay_debugfs_write() for what could be expressed in a
simple sprintf, as Rasmus pointed out.

This drops the leading 0x for each byte, but is otherwise
much nicer.
Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_securedisplay.c

@@ -95,9 +95,7 @@ static ssize_t amdgpu_securedisplay_debugfs_write(struct file *f, const char __u
 	struct drm_device *dev = adev_to_drm(adev);
 	uint32_t phy_id;
 	uint32_t op;
-	int i;
 	char str[64];
-	char i2c_output[256];
 	int ret;
 
 	if (*pos || size > sizeof(str) - 1)
@@ -139,12 +137,9 @@ static ssize_t amdgpu_securedisplay_debugfs_write(struct file *f, const char __u
 		ret = psp_securedisplay_invoke(psp, TA_SECUREDISPLAY_COMMAND__SEND_ROI_CRC);
 		if (!ret) {
 			if (securedisplay_cmd->status == TA_SECUREDISPLAY_STATUS__SUCCESS) {
-				int pos = 0;
-				memset(i2c_output,  0, sizeof(i2c_output));
-				for (i = 0; i < TA_SECUREDISPLAY_I2C_BUFFER_SIZE; i++)
-					pos += sprintf(i2c_output + pos, " 0x%X",
-						securedisplay_cmd->securedisplay_out_message.send_roi_crc.i2c_buf[i]);
-				dev_info(adev->dev, "SECUREDISPLAY: I2C buffer out put is :%s\n", i2c_output);
+				dev_info(adev->dev, "SECUREDISPLAY: I2C buffer out put is: %*ph\n",
+					 TA_SECUREDISPLAY_I2C_BUFFER_SIZE,
+					 securedisplay_cmd->securedisplay_out_message.send_roi_crc.i2c_buf);
 			} else {
 				psp_securedisplay_parse_resp_status(psp, securedisplay_cmd->status);
 			}