Added back the null pointer check.

Author: Daniel K. O. (dkosmari)

source/ButtonComboManager.cpp

@@ -401,7 +401,7 @@ void ButtonComboManager::UpdateInputVPAD(const VPADChan chan, std::span<VPADStat
         DEBUG_FUNCTION_LINE_ERR("Invalid VPADChan");
         return;
     }
-    if (buffer.empty() || !error || *error != VPAD_READ_SUCCESS) {
+    if (!buffer.data() || buffer.empty() || !error || *error != VPAD_READ_SUCCESS) {
         DEBUG_FUNCTION_LINE_ERR("Invalid buffer or error state");
         return;
     }