ALSA: firewire-lib: code refactoring for error path of parser for CIP header

When a parser for CIP header returns -EAGAIN, no extra care is needed
to probe tracepoints event.

This commit adds code refactoring for the error path.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp-stream.c

@@ -635,12 +635,8 @@ static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle,
 		cip_header = ctx_header + 2;
 		err = check_cip_header(s, cip_header, *payload_length,
 				       data_blocks, dbc, syt);
-		if (err < 0) {
-			if (err != -EAGAIN)
-				return err;
-
-			*data_blocks = 0;
-		}
+		if (err < 0)
+			return err;
 	} else {
 		cip_header = NULL;
 		err = 0;
@@ -654,9 +650,6 @@ static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle,
 			*dbc = 0;
 	}
 
-	if (err < 0)
-		return err;
-
 	s->data_block_counter = *dbc;
 
 	trace_amdtp_packet(s, cycle, cip_header, *payload_length, *data_blocks,