Replace memset 0 with initializers.

Test: Compiles and bionic unit tests pass.
Change-Id: I94e178c56d958beeb1c484e4d52d61df022189e8
diff --git a/tests/stack_unwinding_test.cpp b/tests/stack_unwinding_test.cpp
index 2f891a6..fc6c25c 100644
--- a/tests/stack_unwinding_test.cpp
+++ b/tests/stack_unwinding_test.cpp
@@ -43,8 +43,7 @@
   const char* symbol = "<unknown>";
   int offset = 0;
 
-  Dl_info info;
-  memset(&info, 0, sizeof(info));
+  Dl_info info = {};
   if (dladdr(ip, &info) != 0) {
     symbol = info.dli_sname;
     if (info.dli_saddr != nullptr) {