This patch is already merged in dolphin.

It'll appear in libretro-dolphin whenever it is rebased on top of current
dolphin source.

diff --git a/Source/Core/Core/LibusbUtils.cpp b/Source/Core/Core/LibusbUtils.cpp
index a4083e2d06..1ef9777e71 100644
--- a/Source/Core/Core/LibusbUtils.cpp
+++ b/Source/Core/Core/LibusbUtils.cpp
@@ -9,8 +9,8 @@
 #include <libusb.h>
 #endif
 
-#include "Common/Assert.h"
 #include "Common/Flag.h"
+#include "Common/Logging/Log.h"
 #include "Common/Thread.h"
 #include "Core/LibusbUtils.h"
 
@@ -23,9 +23,12 @@ public:
   Impl()
   {
     const int ret = libusb_init(&m_context);
-    ASSERT_MSG(IOS_USB, ret == LIBUSB_SUCCESS, "Failed to init libusb: %s", libusb_error_name(ret));
     if (ret != LIBUSB_SUCCESS)
+    {
+      ERROR_LOG(IOS_USB, "Failed to init libusb: %s", libusb_error_name(ret));
       return;
+    }
+
 
 #ifdef _WIN32
     libusb_set_option(m_context, LIBUSB_OPTION_USE_USBDK);
