Make recently-introduced setters macros.

Make recently-introduced setters macros.

* fontset.c (set_fontset_id, set_fontset_name, set_fontset_ascii)
(set_fontset_base, set_fontset_frame, set_fontset_nofont_face)
(set_fontset_default, set_fontset_fallback): Rename from their
upper-case counterparts, and make them functions rather than macros.
This is more consistent with the other recently-introduced setters.
These don't need to be inline, since they're local.