staging: rtl8712: Replace snprintf with scnprintf

When the number of bytes to be printed exceeds the limit snprintf
returns the number of bytes that would have been printed (if there was
no truncation). This might cause issues, hence use scnprintf which
returns the actual number of bytes printed to buffer always.
Signed-off-by: Rohit Sarkar <rohitsarkar5398@gmail.com>
Link: https://lore.kernel.org/r/20190910184931.GA8228@SARKARSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/rtl871x_ioctl_linux.c

@@ -142,7 +142,7 @@ static noinline_for_stack char *translate_scan_wpa(struct iw_request_info *info,
 		memset(buf, 0, MAX_WPA_IE_LEN);
 		n = sprintf(buf, "wpa_ie=");
 		for (i = 0; i < wpa_len; i++) {
-			n += snprintf(buf + n, MAX_WPA_IE_LEN - n,
+			n += scnprintf(buf + n, MAX_WPA_IE_LEN - n,
 						"%02x", wpa_ie[i]);
 			if (n >= MAX_WPA_IE_LEN)
 				break;
@@ -162,7 +162,7 @@ static noinline_for_stack char *translate_scan_wpa(struct iw_request_info *info,
 		memset(buf, 0, MAX_WPA_IE_LEN);
 		n = sprintf(buf, "rsn_ie=");
 		for (i = 0; i < rsn_len; i++) {
-			n += snprintf(buf + n, MAX_WPA_IE_LEN - n,
+			n += scnprintf(buf + n, MAX_WPA_IE_LEN - n,
 						"%02x", rsn_ie[i]);
 			if (n >= MAX_WPA_IE_LEN)
 				break;