bug#35406: Build error for emacsclient on FreeBSD

[Josh Howard]

It appears in a recent commit there was a change to emacsclient.c that breaks 
its ability to build on FreeBSD by using the euidaccess() function which 
doesn't exist on the platform.

CCLD     emacsclient
emacsclient.c:1475:11: warning: implicit declaration of function 'euidaccess' is
      invalid in C99 [-Wimplicit-function-declaration]
              && euidaccess (sockdirname, X_OK) == 0)
                 ^
1 warning generated.
/usr/bin/ld: error: undefined symbol: euidaccess
>>> referenced by emacsclient.c:1475
>>>               /tmp/emacsclient-a0b189.o:(set_local_socket)
cc: error: linker command failed with exit code 1 (use -v to see invocation)
gmake: *** [Makefile:399: emacsclient] Error 1

I'd propose it be switched to eaccess() which should be a synonym on Linux and 
makes it a bit more portable.

diff --git a/lib-src/emacsclient.c b/lib-src/emacsclient.c
index 5871a18ce6..aac1b3c2b4 100644
--- a/lib-src/emacsclient.c
+++ b/lib-src/emacsclient.c
@@ -1472,7 +1472,7 @@ set_local_socket (char const *server_name)
          int sockdirnamelen = snprintf (sockdirname, sizeof sockdirname,
                                         "/run/user/%"PRIuMAX, id);
          if (0 <= sockdirnamelen && sockdirnamelen < sizeof sockdirname
-             && euidaccess (sockdirname, X_OK) == 0)
+             && eaccess (sockdirname, X_OK) == 0)
            message
              (true,
               ("%s: Should XDG_RUNTIME_DIR='%s' be in the environment?\n"