Add psa_trusted_storage_linux persistent storage support for v1.0.0 APIs

The following provides more information on this PR:
- PSA stands for Platform Security Architecture.
- Add support for use of psa_trusted_storage_api internal_trusted_storage.h v1.0.0
  as the interface to the psa_trusted_storage_linux backend (i.e. for persistent
  storage when MBEDTLS_PSA_ITS_FILE_C is not defined). This requires changes
  to psa_crypto_its.h and psa_crypto_storage.c to migrate to the new API.
diff --git a/library/psa_crypto_storage.c b/library/psa_crypto_storage.c
index babc5bb..3c33c1d 100644
--- a/library/psa_crypto_storage.c
+++ b/library/psa_crypto_storage.c
@@ -96,12 +96,15 @@
     psa_status_t status;
     psa_storage_uid_t data_identifier = psa_its_identifier_of_slot( key );
     struct psa_storage_info_t data_identifier_info;
+    size_t data_length = 0;
 
     status = psa_its_get_info( data_identifier, &data_identifier_info );
     if( status  != PSA_SUCCESS )
         return( status );
 
-    status = psa_its_get( data_identifier, 0, (uint32_t) data_size, data );
+    status = psa_its_get( data_identifier, 0, (uint32_t) data_size, data, &data_length );
+    if( data_size  != data_length )
+        return( PSA_ERROR_STORAGE_FAILURE );
 
     return( status );
 }