Always include <sys/socket.h> before <linux/netlink.h>.

Newer kernel headers files aren't stand alone. (This has long been true of
glibc's copy, but we only recently updated external/kernel-headers.)

Change-Id: Iebcb40902b2f29fe509e207e2f3a9d02a7e40602
diff --git a/charger/charger.c b/charger/charger.c
index abf5517..76be076 100644
--- a/charger/charger.c
+++ b/charger/charger.c
@@ -21,19 +21,20 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/input.h>
-#include <linux/netlink.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/poll.h>
-#include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/un.h>
 #include <time.h>
 #include <unistd.h>
 
+#include <sys/socket.h>
+#include <linux/netlink.h>
+
 #include <cutils/android_reboot.h>
 #include <cutils/klog.h>
 #include <cutils/list.h>