Client binaries do not respect LDFLAGS

[oxr463]

Compiled with the command, LDFLAGS="-Wl,--defsym=__check_ldflags__=0" CLIENT_LDFLAGS="${LDFLAGS}" make.

Output from objdump:

objdump -x lib/libmosquitto.so.1 | grep __check
0000000000011340 l     F .text  000000000000016e              mosquitto__check_keepalive
000000000000ceb0 l     F .text  000000000000003b              packet__check_oversize
0000000000000000 l       *ABS*  0000000000000000              __check_ldflags__
objdump -x client/mosquitto_pub | grep __check
objdump -x client/mosquitto_sub | grep __check
objdump -x client/mosquitto_rr | grep __check

Note: checking for the __check_ldflags__ symbol returned 1 for the client binaries.

[oxr463]

If I pass the -e flag to make it will respect the environment variables.

See also: #1232

[ralight]

You can now do this with just make LDFLAGS="-Wl,--defsym=__check_ldflags__=0" in the fixes branch.