server: explicitly set the function name in lambda (#17538)

server: explicitly set the function name in lambda (#17538)

As [1] explained, the real debug message will be like:
	"res    operator(): operator() : queue result stop"

Set the name explicitly, the message is easy for debugging:
	"res    operator(): recv : queue result stop"

The left "operator()" is generated by 'RES_DBG() ... __func__'

[1]: https://clang.llvm.org/extra/clang-tidy/checks/bugprone/lambda-function-name.html

Signed-off-by: Haiyue Wang <redacted>