tests/pkd: free socket wrapper string upon error

In e1a8b359c1 a missing `free` was
added to `pkd_cleanup_socket_wrapper` to free a string allocated
for the socket wrapper directory name.

Move that `free` such that it also runs in the error-out paths in
`pkd_cleanup_socket_wrapper`, to avoid a leak in those cases, too.

Signed-off-by: Jon Simons <jon@jonsimons.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>

tests/pkd/pkd_hello.c

@@ -1011,12 +1011,12 @@ static int pkd_cleanup_socket_wrapper(void) {
         goto errrmdir;
     }
 
-    free(pkd_dargs.opts.socket_wrapper.mkdtemp_str);
-
-    goto out;
+    goto outfree;
 errrmdir:
 errrmfiles:
     rc = -1;
+outfree:
+    free(pkd_dargs.opts.socket_wrapper.mkdtemp_str);
 out:
     return rc;
 }