out_chg involves redundant operations for the charge output and documentation issues

[Cstandardlib]

Describe the bug

When writing charge density a redundant real2cecip is called.

pw_rhod->real2recip(chr.rho_save[is], chr.rhog_save[is]);

And the doc does not contain out_chg=-1 cases now.

Expected behavior

No response

To Reproduce

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Environment

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Additional Context

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