(init_subshell_child): join, constify and mark as unused chdir return value

Signed-off-by: Yury V. Zaytsev <yury@shurup.com>

Author: zyv

src/subshell/common.c

@@ -300,12 +300,8 @@ init_subshell_child (const char *pty_name)
 
     // It simplifies things to change to our home directory here,
     // and the user's startup file may do a 'cd' command anyway
-    {
-        int ret;
-
-        ret = chdir (mc_config_get_home_dir ());  // FIXME? What about when we re-run the subshell?
-        (void) ret;
-    }
+    // FIXME? What about when we re-run the subshell?
+    MC_UNUSED const int ret_chdir = chdir (mc_config_get_home_dir ());
 
     // Set MC_SID to prevent running one mc from another
     mc_sid = getsid (0);