Replace memset 0 with initializers.

Test: Compiles and bionic unit tests pass.
Change-Id: I94e178c56d958beeb1c484e4d52d61df022189e8
diff --git a/tests/sys_sem_test.cpp b/tests/sys_sem_test.cpp
index 27943cf..0b7a7ff 100644
--- a/tests/sys_sem_test.cpp
+++ b/tests/sys_sem_test.cpp
@@ -47,8 +47,7 @@
   ASSERT_NE(id, -1);
 
   // Check semaphore info.
-  semid_ds ds;
-  memset(&ds, 0, sizeof(ds));
+  semid_ds ds = {};
   ASSERT_EQ(0, semctl(id, 0, IPC_STAT, &ds));
   ASSERT_EQ(1U, ds.sem_nsems);