[PATCH] riscv: fpu: refine FPU save flow

[Mina Chou]

Hi Vivian,

Thanks for the review.

You are right; the sstatus was caused by task_pt_regs(p) being incorrectly
handled in older kernels, but the issue has already been fixed by:

riscv: prevent stack corruption by reserving task_pt_regs(p) early 
(merged in Linux v6.5).

I should have checked the latest master before sending this over. 
My apologies for the noise, please ignore this patch.

Best regards,
Mina