mesa: fix attachment error checking for glGetFramebufferAttachmentParameteriv()

This is a follow-on to commit 80dfec3e53fd5b5c8c31fb16376c9910258c91b0.

The valid attachments for glGetFramebufferAttachmentParameteriv() depends
on whether we're querying the default FBO or a user-created FBO.
1 file changed