gsm48_decode_bcd_number2(): return -EINVAL if LV has too big length

Change-Id: Ie07b2e8bc2f9628904e88448b4ee63b359655123
diff --git a/tests/gsm0408/gsm0408_test.c b/tests/gsm0408/gsm0408_test.c
index 55c9b61..d7bae77 100644
--- a/tests/gsm0408/gsm0408_test.c
+++ b/tests/gsm0408/gsm0408_test.c
@@ -712,7 +712,7 @@
 		.test_name = "LV incorrect length",
 		.dec_hex   = "05214365", /* should be 0x03 */
 		.dec_ascii = "(none)",
-		.dec_rc    = -EIO,
+		.dec_rc    = -EINVAL,
 	},
 	{
 		.test_name = "empty input buffer",