ptp: ocp: use snprintf() in ptp_ocp_verify()

This code is fine, but it's easier to review if we use snprintf()
instead of sprintf().
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/r/20220318074723.GA6617@kiliSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/ptp/ptp_ocp.c

@@ -972,7 +972,7 @@ ptp_ocp_verify(struct ptp_clock_info *ptp_info, unsigned pin,
 
 	switch (func) {
 	case PTP_PF_NONE:
-		sprintf(buf, "IN: None");
+		snprintf(buf, sizeof(buf), "IN: None");
 		break;
 	case PTP_PF_EXTTS:
 		/* Allow timestamps, but require sysfs configuration. */
@@ -982,9 +982,9 @@ ptp_ocp_verify(struct ptp_clock_info *ptp_info, unsigned pin,
 		 * channels 1..4 are the frequency generators.
 		 */
 		if (chan)
-			sprintf(buf, "OUT: GEN%d", chan);
+			snprintf(buf, sizeof(buf), "OUT: GEN%d", chan);
 		else
-			sprintf(buf, "OUT: PHC");
+			snprintf(buf, sizeof(buf), "OUT: PHC");
 		break;
 	default:
 		return -EOPNOTSUPP;