cpplib.h (struct cpp_callbacks): Annotate error with ATTRIBUTE_FPTR_PRINTF(3,0) instead of ATTRIBUTE_PRINTF(3,0).

	* include/cpplib.h (struct cpp_callbacks): Annotate error with
	ATTRIBUTE_FPTR_PRINTF(3,0) instead of ATTRIBUTE_PRINTF(3,0).

Co-Authored-By: Ian Lance Taylor <ian@airs.com>

From-SVN: r106891
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index adae96b..9ec022f 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -474,7 +474,7 @@
   /* Called to emit a diagnostic if client_diagnostic option is true.
      This callback receives the translated message.  */
   void (*error) (cpp_reader *, int, const char *, va_list *)
-       ATTRIBUTE_PRINTF(3,0);
+       ATTRIBUTE_FPTR_PRINTF(3,0);
 };
 
 /* Chain of directories to look for include files in.  */