target/arm: Simplify pstate_sm check in sve_access_check

target/arm: Simplify pstate_sm check in sve_access_check

In StreamingMode, fp_access_checked is handled already.
We cannot fall through to fp_access_check lest we fall
foul of the double-check assertion.

Cc: qemu-stable@nongnu.org
Fixes: 285b1d5fcef ("target/arm: Handle SME in sve_access_check")
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250307190415.982049-3-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: move declaration of 'ret' to top of block]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>