Switch to the new code style

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/include/alt-dummy/threading_alt.h b/tests/include/alt-dummy/threading_alt.h
index ff2fed5..4003506 100644
--- a/tests/include/alt-dummy/threading_alt.h
+++ b/tests/include/alt-dummy/threading_alt.h
@@ -19,8 +19,7 @@
 #ifndef THREADING_ALT_H
 #define THREADING_ALT_H
 
-typedef struct mbedtls_threading_mutex_t
-{
+typedef struct mbedtls_threading_mutex_t {
     int dummy;
 } mbedtls_threading_mutex_t;