Update icd_windows.c (#51)

Return TRUE from khrIcdOsVendorsEnumerate() even if RegOpenKeyExA() fails to open the key.
diff --git a/icd_windows.c b/icd_windows.c
index 9c509ea..5f89085 100644
--- a/icd_windows.c
+++ b/icd_windows.c
@@ -54,7 +54,7 @@
     if (ERROR_SUCCESS != result)
     {
         KHR_ICD_TRACE("Failed to open platforms key %s, continuing\n", platformsName);
-        return FALSE;
+        return TRUE;
     }
 
     // for each value