fix: 修复 smooth 时，line 和 area 线条不一致。Closed: #1835

[zengyue]

Checklist

• [ ] npm test passes
• [ ] tests and/or benchmarks are included
• [ ] commit message follows commit guidelines

Description of change

[github-actions[bot]]

Critical size changes

Includes critical production bundles, as well as any change greater than 2%:

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
f2/dist/index.js	+0.10%	1,635.79 kB	1,637.35 kB	+0.14%	308.25 kB	308.66 kB
f2/dist/index.min.js	+0.09%	511.19 kB	511.63 kB	+0.09%	152.80 kB	152.94 kB

Significant size changes

Includes any change greater than 0.2%: (No significant changes)

Generated by :no_entry_sign: dangerJS against 25c285f9afaa06f74fdb5735608c10db9821a3d4

[firstmetcs]

这个问题可不可以合并修改一下V4版本 @zengyue