spi95: Check for success before using send_command's returned data

If the transfer failed, the data might be invalid.

Change-Id: I3ad9daa00a54e2a3954983cec91b6685f1a98880
Found-By: Coverity Scan #1405870
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/40970
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/67862
Reviewed-by: Felix Singer <felixsinger@posteo.net>
diff --git a/spi95.c b/spi95.c
index ecb2c1d..976f99a 100644
--- a/spi95.c
+++ b/spi95.c
@@ -33,12 +33,15 @@
 	static const unsigned char cmd[ST_M95_RDID_OUTSIZE_MAX] = { ST_M95_RDID };
 	unsigned char readarr[ST_M95_RDID_INSIZE];
 	uint32_t id1, id2;
+	int ret;
 
 	uint32_t rdid_outsize = ST_M95_RDID_2BA_OUTSIZE; // 16 bit address
 	if (flash->chip->total_size * KiB > 64 * KiB)
 		rdid_outsize = ST_M95_RDID_3BA_OUTSIZE; // 24 bit address
 
-	spi_send_command(flash, rdid_outsize, sizeof(readarr), cmd, readarr);
+	ret = spi_send_command(flash, rdid_outsize, sizeof(readarr), cmd, readarr);
+	if (ret)
+		return ret;
 
 	id1 = readarr[0]; // manufacture id
 	id2 = (readarr[1] << 8) | readarr[2]; // SPI family code + model id