Clarify framing errors

src/leansdr/hdlc.h

@@ -52,10 +52,10 @@ namespace leansdr {
 	      // Unstuff this 0
 	    } else if ( shiftreg == 0x7e ) {  // 01111110 HDLC flag
 	      if ( nbits_out != 7 ) {
-		if ( debug ) fprintf(stderr, "?");
+		// Not at byte boundary
+		if ( debug ) fprintf(stderr, "^");
 		++*hdlc_errors;
-	      }
-	      nbits_out = 0;
+	      } else {
 		// Checksum
 		crc16 ^= 0xffff;
 		if ( framesize<2 || framesize<minframesize ||
@@ -66,8 +66,11 @@ namespace leansdr {
 		  if ( framesize >= minframesize ) ++*fcs_errors;
 		} else {
 		  if ( debug ) fprintf(stderr, "_");
+		  // This will trigger output, but we finish the byte first.
 		  *pdatasize = framesize-2;
 		}
+	      }
+	      nbits_out = 0;
 	      begin_frame();
 	      // Keep processing up to 7 remaining bits from byte_in.
 	      // Special cases 0111111 and 1111111 cannot affect *pdatasize.