Replace memset 0 with initializers.

Test: Compiles and bionic unit tests pass.
Change-Id: I94e178c56d958beeb1c484e4d52d61df022189e8
diff --git a/tests/ifaddrs_test.cpp b/tests/ifaddrs_test.cpp
index da64770..01779f7 100644
--- a/tests/ifaddrs_test.cpp
+++ b/tests/ifaddrs_test.cpp
@@ -116,9 +116,7 @@
 
 static void CheckAddressIsInSet(const std::string& if_name, bool unicast,
                                 const std::set<in_addr_t>& addrs) {
-  ifreq ifr;
-  memset(&ifr, 0, sizeof(ifr));
-  ifr.ifr_addr.sa_family = AF_INET;
+  ifreq ifr = {.ifr_addr.sa_family = AF_INET};
   if_name.copy(ifr.ifr_name, IFNAMSIZ - 1);
 
   int fd = socket(AF_INET, SOCK_DGRAM, 0);