c-strtod, memcoll, readutmp: no 'static inline'

c-strtod, memcoll, readutmp: no 'static inline'

* lib/c-strtod.c (c_locale):
* lib/memcoll.c (strcoll_loop):
* lib/readutmp.c (desirable_utmp_entry):
Now static, not static inline.
* m4/c-strtod.m4 (gl_C_STRTOD, gl_C_STRTOLD):
* m4/memcoll.m4 (gl_MEMCOLL):
* m4/readutmp.m4 (gl_READUTMP):
Do not require AC_C_INLINE.