malloc_simple: fix malloc_ptr calculation

The gd->malloc_ptr and the gd->malloc_limit are offsets to gd->malloc_base.
But the addr variable contains the absolute address. The new_ptr must be:
addr + bytes - gd->malloc_base.

Signed-off-by: Philipp Rosenberger <ilu@linutronix.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

common/malloc_simple.c

@@ -32,7 +32,7 @@ void *memalign_simple(size_t align, size_t bytes)
 	void *ptr;
 
 	addr = ALIGN(gd->malloc_base + gd->malloc_ptr, align);
-	new_ptr = addr + bytes;
+	new_ptr = addr + bytes - gd->malloc_base;
 	if (new_ptr > gd->malloc_limit)
 		return NULL;
 	ptr = map_sysmem(addr, bytes);