spl: Correct call to spl_common_init() with SPL_STACK_R_MALLOC_SIMPLE_LEN

Calls to IS_ENABLED() on a non-y/n option will always be false, even
when set.  We can correct this by adding a new bool value that is set
based on the conditions required for SPL_STACK_R_MALLOC_SIMPLE_LEN to be
set instead.

Fixes: 340f418a ("spl: Add spl_early_init()")
Reported-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
---
Changes in v2:
- Fix thinko pointed out by Lokesh

common/spl/spl.c

@@ -227,10 +227,11 @@ int spl_early_init(void)
 int spl_init(void)
 {
 	int ret;
+	bool setup_malloc = !(IS_ENABLED(CONFIG_SPL_STACK_R) &&
+			IS_ENABLED(CONFIG_SPL_SYS_MALLOC_SIMPLE));
 
 	if (!(gd->flags & GD_FLG_SPL_EARLY_INIT)) {
-		ret = spl_common_init(
-			!IS_ENABLED(CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN));
+		ret = spl_common_init(setup_malloc);
 		if (ret)
 			return ret;
 	}