rsyslog-config: fix memory leak in addressValid
rsyslog-config: fix memory leak in addressValid

Fixed memory leak reported by LeakSanitizer by using 'freeaddrinfo'
after corresponding 'getaddrinfo' call.

    ERROR: LeakSanitizer: detected memory leaks

    Direct leak of 64 byte(s) in 1 object(s) allocated from:
        #0 0x7f9e9ccba727 in __interceptor_malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/10.3.0/libasan.so.6+0xb1727)
        #1 0x7f9e957dbd07  (/lib64/libc.so.6+0xe5d07)
        #2 0x7f9e957dd08b in getaddrinfo (/lib64/libc.so.6+0xe708b)
        #3 0x7f9e9cc940aa  (/usr/lib/gcc/x86_64-pc-linux-gnu/10.3.0/libasan.so.6+0x8b0aa)
        #4 0x5619f832d16f in phosphor::rsyslog_config::Server::addressValid(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ../phosphor-rsyslog-config/server-conf.cpp:121

Signed-off-by: Patrick Williams <cbb7353e6d953ef360baf960c122346276c6e320@stwcx.xyz>
Change-Id: Ia7984cd6516ffbe57ed2859fee98366fa3a90f9e

openbmc/phosphor-logging,openbmc/phosphor-logging,openbmc/phosphor-logging,openbmc/phosphor-logging