linux-user: pass correct host flags to eventfd2 call

This change makes conversion of TARGET_O_NONBLOCK and TARGET_O_CLOEXEC flags
to host flags before calling eventfd for TARGET_NR_eventfd2.
Signed-off-by: NPetar Jovanovic <petar.jovanovic@imgtec.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

linux-user/syscall.c

@@ -8823,8 +8823,17 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 #endif
 #if defined(TARGET_NR_eventfd2)
     case TARGET_NR_eventfd2:
-        ret = get_errno(eventfd(arg1, arg2));
+    {
+        int host_flags = arg2 & (~(TARGET_O_NONBLOCK | TARGET_O_CLOEXEC));
+        if (arg2 & TARGET_O_NONBLOCK) {
+            host_flags |= O_NONBLOCK;
+        }
+        if (arg2 & TARGET_O_CLOEXEC) {
+            host_flags |= O_CLOEXEC;
+        }
+        ret = get_errno(eventfd(arg1, host_flags));
         break;
+    }
 #endif
 #endif /* CONFIG_EVENTFD  */
 #if defined(CONFIG_FALLOCATE) && defined(TARGET_NR_fallocate)