system/core LP64 cleanup.

Fixes -Wint-to-pointer and -Wpointer-to-int warnings, plus various -Wformat
warnings.

Change-Id: I6c5eea6b4273d82d28b8e5d2925f3e5457511b17
diff --git a/fastbootd/protocol.c b/fastbootd/protocol.c
index 0086b4a..3908020 100644
--- a/fastbootd/protocol.c
+++ b/fastbootd/protocol.c
@@ -142,7 +142,7 @@
     char response[64];
     ssize_t ret;
 
-    snprintf(response, 64, "DATA%08x", len);
+    snprintf(response, 64, "DATA%08zx", len);
     ret = protocol_handle_write(phandle, response, strlen(response));
     if (ret < 0)
         return;