RISC-V: Fix local_eliminate_vsetvl_insn bug in VSETVL PASS[PR target/110560]

This patch fixes this issue happens on GCC-13.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110560

This patch should be backported to GCC-13.
GCC-14 has rewritten this function, so there is no issue.

gcc/ChangeLog:

	PR target/110560
	* config/riscv/riscv-vsetvl.cc (local_eliminate_vsetvl_insn): Fix bug.