Check all lseek calls succeed.

Also add missing TEMP_FAILURE_RETRYs on read, write, and lseek.

Bug: http://b/20625546
Change-Id: I03b198e11c1921b35518ee2dd005a7cfcf4fd94b
(cherry picked from commit 7bad7c4646)

ui.cpp

@@ -251,7 +251,7 @@ bool RecoveryUI::IsUsbConnected() {
 
     char buf;
     // USB is connected if android_usb state is CONNECTED or CONFIGURED.
-    int connected = (read(fd, &buf, 1) == 1) && (buf == 'C');
+    int connected = (TEMP_FAILURE_RETRY(read(fd, &buf, 1)) == 1) && (buf == 'C');
     if (close(fd) < 0) {
         printf("failed to close /sys/class/android_usb/android0/state: %s\n",
                strerror(errno));