tty: n_gsm: Improve debug output

Use appropriate print helpers for debug messages.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20200512115323.1447922-2-gregory.clement@bootlin.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/n_gsm.c

@@ -504,18 +504,8 @@ static void gsm_print_packet(const char *hdr, int addr, int cr,
 	else
 		pr_cont("(F)");
 
-	if (dlen) {
-		int ct = 0;
-		while (dlen--) {
-			if (ct % 8 == 0) {
-				pr_cont("\n");
-				pr_debug("    ");
-			}
-			pr_cont("%02X ", *data++);
-			ct++;
-		}
-	}
-	pr_cont("\n");
+	if (dlen)
+		print_hex_dump_bytes("", DUMP_PREFIX_NONE, data, dlen);
 }