Fix logspam from system-background cpuset.

system-background can't be opened by most processes, since system-bg is
a privileged cpuset. Remove the log message when it can't be
opened. We'll still log a failure to use the fd if we try to use it
after it can't be opened, which is fine.

bug 26249842

Change-Id: I99f185c51645bc81b6a41732848227c27675cdf7
diff --git a/libcutils/sched_policy.c b/libcutils/sched_policy.c
index 8c26cdd..70dc8c4 100644
--- a/libcutils/sched_policy.c
+++ b/libcutils/sched_policy.c
@@ -129,9 +129,6 @@
         bg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
         filename = "/dev/cpuset/system-background/tasks";
         system_bg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
-        if (system_bg_cpuset_fd < 0) {
-            SLOGE("initialize of system-bg failed: %s\n", strerror(errno));
-        }
     }
 #endif