testsuite/i386: Fix XOP and FMA4 checking functions [PR98036].

testsuite/i386: Fix XOP and FMA4 checking functions [PR98036].

Add missing returns and remove unnecessary postfix increments.

2020-11-27  Uroš Bizjak  <ubizjak@gmail.com>

	PR testsuite/98036

gcc/testsuite/
	* gcc.target/i386/fma4-256-maccXX.c (check_maccps):
	Remove unnecessary postfix increment on a returned variable.
	(check_maccpd): Ditto.
	* gcc.target/i386/fma4-256-msubXX.c (check_msubps): Ditto.
	(check_msubpd): Ditto.
	* gcc.target/i386/fma4-256-nmaccXX.c (check_nmaccps): Ditto.
	(check_nmaccpd): Ditto.
	* gcc.target/i386/fma4-256-nmsubXX.c (check_nmsubps): Ditto.
	(check_nmsubpd): Ditto.
	* gcc.target/i386/fma4-maccXX.c (check_maccps): Ditto.
	(check_maccpd): Ditto.
	(check_maccss): Ditto.
	(check_maccsd): Ditto.
	* gcc.target/i386/fma4-msubXX.c (check_msubps): Ditto.
	(check_msubpd): Ditto.
	(check_msubss): Ditto.
	(check_msubsd): Ditto.
	* gcc.target/i386/fma4-nmaccXX.c (check_nmaccps): Ditto.
	(check_nmaccpd): Ditto.
	(check_nmaccss): Ditto.
	(check_nmaccsd): Ditto.
	* gcc.target/i386/fma4-nmsubXX.c (check_nmsubps): Ditto.
	(check_nmsubpd): Ditto.
	(check_nmsubss): Ditto.
	(check_nmsubsd): Ditto.
	* gcc.target/i386/xop-haddX.c (check_sbyte2word): Add missing return.
	(check_sbyte2dword):
	Remove unnecessary postfix increment on a returned value.
	(check_sbyte2qword): Ditto.
	(check_sword2dword): Add missing return.
	(check_sword2qword):
	Remove unnecessary postfix increment on a returned value.
	(check_dword2qword): Add missing return.
	* gcc.target/i386/xop-hadduX.c (check_byte2word): Add missing return.
	(check_byte2dword):
	Remove unnecessary postfix increment on a returned value.
	(check_byte2qword): Ditto.
	(check_word2dword): Add missing return.
	(check_word2qword):
	Remove unnecessary postfix increment on a returned value.
	(check_word2qword): Add missing return.
	* gcc.target/i386/xop-hsubX.c (check_sbyte2word): Add missing return.
	(check_sword2dword): Ditto.
	(check_sword2qword): Ditto.