Add small fixes to iop key agreement APIs

Signed-off-by: Waleed Elmelegy <waleed.elmelegy@arm.com>
diff --git a/tf-psa-crypto/core/psa_crypto.c b/tf-psa-crypto/core/psa_crypto.c
index 285880a..81c33cc 100644
--- a/tf-psa-crypto/core/psa_crypto.c
+++ b/tf-psa-crypto/core/psa_crypto.c
@@ -7862,6 +7862,9 @@
         psa_key_agreement_iop_abort_internal(operation);
         return status;
     }
+    if (unlock_status != PSA_SUCCESS) {
+        operation->error_occurred = 1;
+    }
     return unlock_status;
 #else
     (void) operation;
@@ -7904,7 +7907,7 @@
         operation->error_occurred = 1;
         psa_key_agreement_iop_abort_internal(operation);
     }
-    mbedtls_platform_zeroize(intermediate_key, PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE);
+    mbedtls_platform_zeroize(intermediate_key, sizeof(intermediate_key));
     return status;
 #else
     (void) operation;
@@ -7924,7 +7927,6 @@
 
     operation->num_ops = 0;
     operation->error_occurred = 0;
-    operation->id = 0;
 
     return status;
 #else