oem-ibm: fixup error codes as per spec

Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
Change-Id: If460b3d8ad5863de5437aa727bf30ec4c7715717
diff --git a/oem/ibm/libpldm/file_io.c b/oem/ibm/libpldm/file_io.c
index 69aed29..02adc80 100644
--- a/oem/ibm/libpldm/file_io.c
+++ b/oem/ibm/libpldm/file_io.c
@@ -195,7 +195,7 @@
 	}
 
 	if (length == 0) {
-		return PLDM_INVALID_READ_LENGTH;
+		return PLDM_ERROR_INVALID_LENGTH;
 	}
 
 	if ((rc = pack_pldm_header(&header, &(msg->hdr))) > PLDM_SUCCESS) {
@@ -317,7 +317,7 @@
 	}
 
 	if (length == 0) {
-		return PLDM_INVALID_WRITE_LENGTH;
+		return PLDM_ERROR_INVALID_LENGTH;
 	}
 
 	struct pldm_write_file_req *request =