Linux: Add proper casts for varargs call.

Test: vogar --mode=host --variant=x[32|64] OsTest
Bug: 64473964

(cherry picked from commit c30e11473bdb65fca5dd876753238462676a417e)

Change-Id: I5e3b216a01fc2a20dac79a7ac5196851d0f5dbeb
diff --git a/luni/src/main/native/libcore_io_Linux.cpp b/luni/src/main/native/libcore_io_Linux.cpp
index 1d47a9b..26b7697 100644
--- a/luni/src/main/native/libcore_io_Linux.cpp
+++ b/luni/src/main/native/libcore_io_Linux.cpp
@@ -1324,7 +1324,9 @@
 
     ScopedLocalRef<jclass> rlimit_class(env, env->FindClass("android/system/StructRlimit"));
     jmethodID ctor = env->GetMethodID(rlimit_class.get(), "<init>", "(JJ)V");
-    return env->NewObject(rlimit_class.get(), ctor, r.rlim_cur, r.rlim_max);
+    return env->NewObject(rlimit_class.get(), ctor,
+                          static_cast<jlong>(r.rlim_cur),
+                          static_cast<jlong>(r.rlim_max));
 }
 
 static jobject Linux_getsockname(JNIEnv* env, jobject, jobject javaFd) {