Fix code style in psa_ff_server.c

Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
diff --git a/tests/psa-client-server/psasim/src/psa_ff_server.c b/tests/psa-client-server/psasim/src/psa_ff_server.c
index 16e6058..219722a 100644
--- a/tests/psa-client-server/psasim/src/psa_ff_server.c
+++ b/tests/psa-client-server/psasim/src/psa_ff_server.c
@@ -478,7 +478,7 @@
             sending = MAX_FRAGMENT_SIZE - (sizeof(size_t) * 2);
         }
 
-        INFO("Server: sending %lu bytes to client, sofar = %lu", sending, (long)sofar);
+        INFO("Server: sending %lu bytes to client, sofar = %lu", sending, (long) sofar);
 
         send_msg(msg_handle, WRITE_REQUEST, outvec_idx, sending, buffer + sofar, sending);