[RISC-V] Fix risc-v expected test output after recent iv changes

Richard S's recent change to iv increment insertion removed a reg->reg move
(which was its intent AFAICT).  This triggered a failure on a riscv test.

That test was meant to verify that we didn't have an extraneous reg->reg move
due to a buglet in the risc-v splitters.  Before the 2023 change we had two
vector reg->reg moves and after the 2023 fix we had just one.  With Richard's
change we have none ;-)  Adjusting test accordingly.

Pushed to the trunk.

gcc/testsuite
	* gcc.target/riscv/rvv/autovec/madd-split2-1.c: Update expected
	output.