SSL async tests: tighten a few log checks in some test cases
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index bf7d914..cf2c168 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -4237,6 +4237,7 @@
             1 \
             -s "Async sign callback: injected error" \
             -S "Async resume" \
+            -S "Async cancel" \
             -s "! mbedtls_ssl_handshake returned"
 
 requires_config_enabled MBEDTLS_SSL_ASYNC_PRIVATE
@@ -4259,6 +4260,7 @@
             1 \
             -s "Async sign callback: using key slot " \
             -s "Async resume callback: sign done but injected error" \
+            -S "Async cancel" \
             -s "! mbedtls_ssl_handshake returned"
 
 requires_config_enabled MBEDTLS_SSL_ASYNC_PRIVATE
@@ -4295,6 +4297,7 @@
              [ \$? -eq 1 ] &&
              $P_CLI force_ciphersuite=TLS-ECDHE-RSA-WITH-AES-128-CBC-SHA256" \
             0 \
+            -s "Async sign callback: using key slot 0"
             -S "Async resume" \
             -s "Async cancel" \
             -s "! mbedtls_ssl_handshake returned" \