Fix EINTR handling in clock_nanosleep

clock_nanosleep return errno directly
instead of -1 with errno set

Test: Build ok
Change-Id: I779f2a8234b3dae46d64efee2210b7a2c5a92043
diff --git a/drm/VSyncWorker.cpp b/drm/VSyncWorker.cpp
index 6e92838..ed5fd9b 100644
--- a/drm/VSyncWorker.cpp
+++ b/drm/VSyncWorker.cpp
@@ -101,7 +101,7 @@
   vsync.tv_nsec = int(phased_timestamp - (vsync.tv_sec * kOneSecondNs));
   do {
     ret = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &vsync, nullptr);
-  } while (ret == -1 && errno == EINTR);
+  } while (ret == EINTR);
   if (ret)
     return ret;