mesa: fix error value in GetFramebufferAttachmentParameteriv for OpenGL ES 3.0

mesa: fix error value in GetFramebufferAttachmentParameteriv for OpenGL ES 3.0

Section 6.1.13 "Framebuffer Object Queries" of OpenGL ES 3.0 spec:

 "If the default framebuffer is bound to target, then attachment must be
  BACK, identifying the color buffer; DEPTH, identifying the depth buffer; or
  STENCIL, identifying the stencil buffer."

OpenGL ES 3.0, section 2.5 (GL Errors):

 "If a command that requires an enumerated value is passed a
  symbolic constant that is not one of those specified as allowable
  for that command, an INVALID_ENUM error is generated."

Then change the returned error to INVALID_ENUM.

Fixes:

dEQP-GLES3.functional.fbo.api.attachment_query_default_fbo

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>