builtin/fetch cleanup: always set default value for submodule recursing

The check for the default was introduced with 88a21979c5 (fetch/pull:
recurse into submodules when necessary, 2011-03-06), which replaced an
older construct (builtin/fetchs own implementation of the super-prefix)
introduced in be254a0ea9 (Add the 'fetch.recurseSubmodules' config setting,
2010-11-11) which made sense at the time as there was no default fetch
option for submodules at the time.

Set builtin/fetch.c#recurse_submodules_default to the same value as
submodule.c#config_fetch_recurse_submodules which is set via
set_config_fetch_recurse_submodules, such that the condition for checking
whether we have to set the default value becomes unnecessary.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fetch.c

@@ -49,7 +49,7 @@ static struct transport *gtransport;
 static struct transport *gsecondary;
 static const char *submodule_prefix = "";
 static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
-static int recurse_submodules_default = RECURSE_SUBMODULES_DEFAULT;
+static int recurse_submodules_default = RECURSE_SUBMODULES_ON_DEMAND;
 static int shown_url = 0;
 static int refmap_alloc, refmap_nr;
 static const char **refmap_array;
@@ -1336,8 +1336,7 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 		deepen = 1;
 
 	if (recurse_submodules != RECURSE_SUBMODULES_OFF) {
-		if (recurse_submodules_default != RECURSE_SUBMODULES_DEFAULT)
-			set_config_fetch_recurse_submodules(recurse_submodules_default);
+		set_config_fetch_recurse_submodules(recurse_submodules_default);
 		gitmodules_config();
 		git_config(submodule_config, NULL);
 	}