Merge "fastboot: Fix hang when sparse images end in small chunks."

am: d0d7d0a6b9

Change-Id: Ia98cc2ed8f09ad99aa8d00ba7edb16553827556c

fastboot/fastboot_driver.cpp

@@ -462,6 +462,10 @@ RetCode FastBootDriver::SendBuffer(const std::vector<char>& buf) {
 }
 
 RetCode FastBootDriver::SendBuffer(const void* buf, size_t size) {
+    if (!size) {
+        return SUCCESS;
+    }
+
     // Write the buffer
     ssize_t tmp = transport->Write(buf, size);