The mcycle/minstret counter's stop flag is mistakenly updated on a copy
on stack. Thus the counter increments even when the CY/IR bit in the
mcountinhibit register is set. This commit corrects its behavior.
Fixes: 3780e33732f88 (target/riscv: Support mcycle/minstret write operation) Signed-off-by: Xu Lu <luxu.kernel@bytedance.com> Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>