sfc: Consistently report short MCDI responses as EIO

In some cases failing functions were returning 0 which is obviously wrong.
In other cases they were returning inappropriate error codes.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/mcdi.c b/drivers/net/sfc/mcdi.c
index c48669c..1344afa 100644
--- a/drivers/net/sfc/mcdi.c
+++ b/drivers/net/sfc/mcdi.c
@@ -613,7 +613,7 @@
 	}
 
 	if (outlength < MC_CMD_GET_VERSION_V1_OUT_LEN) {
-		rc = -EMSGSIZE;
+		rc = -EIO;
 		goto fail;
 	}
 
@@ -647,8 +647,10 @@
 			  outbuf, sizeof(outbuf), &outlen);
 	if (rc)
 		goto fail;
-	if (outlen < MC_CMD_DRV_ATTACH_OUT_LEN)
+	if (outlen < MC_CMD_DRV_ATTACH_OUT_LEN) {
+		rc = -EIO;
 		goto fail;
+	}
 
 	if (was_attached != NULL)
 		*was_attached = MCDI_DWORD(outbuf, DRV_ATTACH_OUT_OLD_STATE);
@@ -676,7 +678,7 @@
 		goto fail;
 
 	if (outlen < MC_CMD_GET_BOARD_CFG_OUT_LEN) {
-		rc = -EMSGSIZE;
+		rc = -EIO;
 		goto fail;
 	}
 
@@ -738,8 +740,10 @@
 			  outbuf, sizeof(outbuf), &outlen);
 	if (rc)
 		goto fail;
-	if (outlen < MC_CMD_NVRAM_TYPES_OUT_LEN)
+	if (outlen < MC_CMD_NVRAM_TYPES_OUT_LEN) {
+		rc = -EIO;
 		goto fail;
+	}
 
 	*nvram_types_out = MCDI_DWORD(outbuf, NVRAM_TYPES_OUT_TYPES);
 	return 0;
@@ -765,8 +769,10 @@
 			  outbuf, sizeof(outbuf), &outlen);
 	if (rc)
 		goto fail;
-	if (outlen < MC_CMD_NVRAM_INFO_OUT_LEN)
+	if (outlen < MC_CMD_NVRAM_INFO_OUT_LEN) {
+		rc = -EIO;
 		goto fail;
+	}
 
 	*size_out = MCDI_DWORD(outbuf, NVRAM_INFO_OUT_SIZE);
 	*erase_size_out = MCDI_DWORD(outbuf, NVRAM_INFO_OUT_ERASESIZE);
@@ -968,7 +974,7 @@
 	if (rc)
 		return rc;
 	if (outlen < MC_CMD_GET_ASSERTS_OUT_LEN)
-		return -EINVAL;
+		return -EIO;
 
 	/* Print out any recorded assertion state */
 	flags = MCDI_DWORD(outbuf, GET_ASSERTS_OUT_GLOBAL_FLAGS);
@@ -1086,7 +1092,7 @@
 		goto fail;
 
 	if (outlen < MC_CMD_WOL_FILTER_SET_OUT_LEN) {
-		rc = -EMSGSIZE;
+		rc = -EIO;
 		goto fail;
 	}
 
@@ -1121,7 +1127,7 @@
 		goto fail;
 
 	if (outlen < MC_CMD_WOL_FILTER_GET_OUT_LEN) {
-		rc = -EMSGSIZE;
+		rc = -EIO;
 		goto fail;
 	}