osmo_e1f: Fix inverted logic of E bits

A value of '1' means _no_ CRC4 error observed. We got that right
in the receive side, but not in the transmit side so far

Change-Id: I5ef9ef3b9781da2f53f54253d31cdbf81957ea67
diff --git a/software/obsolete/osmo_e1f.c b/software/obsolete/osmo_e1f.c
index a4cadb2..2c3fcfb 100644
--- a/software/obsolete/osmo_e1f.c
+++ b/software/obsolete/osmo_e1f.c
@@ -233,7 +233,7 @@
 		case 13:
 		case 15:
 			ret = 0x40;
-			if (e1i->tx.crc4_error)
+			if (!e1i->tx.crc4_error)
 				ret |= 0x80;
 			break;
 		}