tls_handshake_tests.py: Fix expected server log

The TLS 1.2 ClientHello function does not return
at the end in case of parsing error. Thus adapt
the server expected log in case of too small
fragments.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>

scripts/mbedtls_framework/tls_handshake_tests.py

@@ -107,7 +107,7 @@ def write_tls_handshake_defragmentation_test(
             'SSL - An invalid SSL record was received',
         ]
         if side == Side.SERVER:
-            wanted_patterns[0:0] = ['<= parse client hello']
+            wanted_patterns[0:0] = ['=> parse client hello']
         elif version == Version.TLS13:
             wanted_patterns[0:0] = ['=> ssl_tls13_process_server_hello']
     else: