ada: Remove extra parentheses

In preparation of enhancing -gnatyx to check for these automatically.

gcc/ada/

	* ali-util.adb, par-endh.adb, par-prag.adb, par-ch2.adb,
	checks.adb, fmap.adb, libgnat/a-nbnbig.ads, libgnat/g-dynhta.adb,
	libgnat/s-carun8.adb, libgnat/s-strcom.adb, libgnat/a-dhfina.adb,
	libgnat/a-direct.adb, libgnat/a-rbtgbo.adb, libgnat/a-strsea.adb,
	libgnat/a-ststio.adb, libgnat/a-suenco.adb, libgnat/a-costso.adb,
	libgnat/a-strmap.adb, libgnat/g-alleve.adb,
	libgnat/g-debpoo.adb, libgnat/g-sercom__linux.adb,
	libgnat/s-genbig.adb, libgnat/s-mmap.adb, libgnat/s-regpat.adb,
	par-ch5.adb, sem_case.adb, sem_ch12.adb, sem_ch13.adb,
	sem_ch8.adb, sem_eval.adb, sem_prag.adb, sem_type.adb,
	exp_ch11.adb, exp_ch2.adb, exp_ch3.adb, exp_ch4.adb, exp_ch5.adb,
	exp_ch6.adb, exp_ch9.adb, exp_put_image.adb, freeze.adb, live.adb,
	sem_aggr.adb, sem_cat.adb, sem_ch10.adb, sem_ch3.adb, sem_ch6.adb,
	sem_ch9.adb, sem_disp.adb, sem_elab.adb, sem_res.adb,
	sem_util.adb, sinput.adb, uintp.adb, bcheck.adb, binde.adb,
	binderr.adb, einfo-utils.adb, clean.adb, sem_ch4.adb, gnatls.adb,
	gprep.adb, sem_ch11.adb: Remove extra parentheses.