Avoid compiler warning in emacsclient.c

* lib-src/emacsclient.c (socket_name): Define only if
NO_SOCKETS_IN_FILE_SYSTEM is not defined, to avoid a compiler
warning.
1 job for master in 60 minutes and 1 second (queued for 3 seconds)
Status Job ID Name Coverage
  Test
failed #99
test

01:00:01

 
Name Stage Failure
failed
test Test
  GEN      src/marker-tests.log
ELC src/minibuf-tests.elc
GEN src/minibuf-tests.log
ELC src/print-tests.elc
GEN src/print-tests.log
ELC src/process-tests.elc
GEN src/process-tests.log
Pulling docker image gitlab/gitlab-runner-helper:x86_64-cf91d5e1 ...
ERROR: Job failed: execution took longer than 1h0m0s seconds