intel: allow cmd building to record an error

Generalize "bool grow_fail" to "XGL_RESULT result" to record the last error.
diff --git a/icd/intel/cmd.h b/icd/intel/cmd.h
index f466609..9a7025b 100644
--- a/icd/intel/cmd.h
+++ b/icd/intel/cmd.h
@@ -40,7 +40,7 @@
     uint32_t *ptr;
 
     XGL_UINT used, size;
-    bool grow_failed;
+    XGL_RESULT result;
 };
 
 static inline struct intel_cmd *intel_cmd(XGL_CMD_BUFFER cmd)