Fix Linux build

Source/Engine/Platform/Linux/LinuxPlatform.cpp

@@ -2016,6 +2016,7 @@ bool LinuxPlatform::Init()
     ASSERT(UnixCpu.CacheLineSize && Math::IsPowerOfTwo(UnixCpu.CacheLineSize));
 
     // Get user name string
+    char buffer[UNIX_APP_BUFF_SIZE];
     getlogin_r(buffer, UNIX_APP_BUFF_SIZE);
     OnPlatformUserAdd(New<User>(String(buffer));
 
@@ -2043,8 +2044,6 @@ bool LinuxPlatform::Init()
         DeviceId.D = (uint32)UnixCpu.ClockSpeed * UnixCpu.LogicalProcessorCount * UnixCpu.ProcessorCoreCount * UnixCpu.CacheLineSize;
     }
 
-    char buffer[UNIX_APP_BUFF_SIZE];
-
     // Get user locale string
     setlocale(LC_ALL, "");
     const char* locale = setlocale(LC_CTYPE, NULL);