rpmsg_ping.c is blocking CI checks for RPTUN related patches like #11673.
this patch simply fix the compilation issue of rpmsg_ping.c:
- line 191: overflow conversion from "long unsigned int" to "unsigned int"
- line 226: "sendlen" used uninitialized
Signed-off-by: Yanfeng Liu <yfliu2008@qq.com>
b258680949