Prefer INLINE functions in font.h to match style used in lisp.h

Prefer INLINE functions in font.h to match style used in lisp.h

* font.h (FONTP, FONT_SPEC_P, FONT_ENTITY_P, FONT_OBJECT_P)
(CHECK_FONT, CHECK_FONT_SPEC, CHECK_FONT_ENTITY, CHECK_FONT_OBJECT)
(XFONT_SPEC, XFONT_ENTITY, XFONT_OBJECT, CHECK_FONT_GET_OBJECT):
Now functions.
* font.c (Ffont_otf_alternates, Fquery_font, Ffont_get_glyphs):
* ftfont.c (ftfont_shape):
* macfont.m (macfont_shape):
* w32uniscribe.c (uniscribe_shape):
* xftfont.c (xftfont_shape): Adjust CHECK_FONT_GET_OBJECT users.