ssl_tls: add key destruction upon generator failure

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index d0fadfd..cbb3c62 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -550,7 +550,10 @@
 
     status = psa_generator_abort( &generator );
     if( status != PSA_SUCCESS )
+    {
+        psa_destroy_key( master_slot );
         return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
+    }
 
     status = psa_destroy_key( master_slot );
     if( status != PSA_SUCCESS )