sreal: Fix typo in function name

sreal: Fix typo in function name

My earlier version of the ipa_bits removal patch resulted in self-test
failures in sreal.  When debugging it, I was really confused that I couldn't
find verify_arithmetics function in the source.  Turns out it had bad
spelling...

2023-10-05  Jakub Jelinek  <jakub@redhat.com>

	* sreal.cc (verify_aritmetics): Rename to ...
	(verify_arithmetics): ... this.
	(sreal_verify_arithmetics): Adjust caller.