DOC: Fix code example in c-info.python-as-glue.rst.
DOC: Fix code example in c-info.python-as-glue.rst.

Corrections to #8023.

- Fix index types to ssize_t.
- Clean up C code style.

Closes #7701.

[ci skip]

pizzathief/numpy,madphysicist/numpy,gfyoung/numpy,pbrod/numpy,rgommers/numpy,charris/numpy,utke1/numpy,endolith/numpy,simongibbons/numpy,pbrod/numpy,pdebuyl/numpy,rgommers/numpy,abalkin/numpy,anntzer/numpy,charris/numpy,shoyer/numpy,rgommers/numpy,MSeifert04/numpy,pdebuyl/numpy,seberg/numpy,seberg/numpy,endolith/numpy,simongibbons/numpy,Eric89GXL/numpy,MSeifert04/numpy,WarrenWeckesser/numpy,grlee77/numpy,b-carter/numpy,WarrenWeckesser/numpy,ahaldane/numpy,anntzer/numpy,abalkin/numpy,grlee77/numpy,mhvk/numpy,MSeifert04/numpy,pbrod/numpy,pbrod/numpy,jorisvandenbossche/numpy,numpy/numpy,madphysicist/numpy,ddasilva/numpy,pdebuyl/numpy,ddasilva/numpy,ContinuumIO/numpy,ddasilva/numpy,ssanderson/numpy,jakirkham/numpy,endolith/numpy,ahaldane/numpy,mhvk/numpy,Eric89GXL/numpy,bringingheavendown/numpy,pdebuyl/numpy,MSeifert04/numpy,ssanderson/numpy,jorisvandenbossche/numpy,pizzathief/numpy,b-carter/numpy,utke1/numpy,bertrand-l/numpy,Eric89GXL/numpy,tynn/numpy,jakirkham/numpy,anntzer/numpy,grlee77/numpy,behzadnouri/numpy,jorisvandenbossche/numpy,ahaldane/numpy,solarjoe/numpy,mhvk/numpy,endolith/numpy,ContinuumIO/numpy,chatcannon/numpy,b-carter/numpy,mattip/numpy,ahaldane/numpy,ssanderson/numpy,bringingheavendown/numpy,shoyer/numpy,solarjoe/numpy,ahaldane/numpy,jakirkham/numpy,gfyoung/numpy,gfyoung/numpy,charris/numpy,mattip/numpy,shoyer/numpy,madphysicist/numpy,mattip/numpy,bertrand-l/numpy,tynn/numpy,rgommers/numpy,tynn/numpy,WarrenWeckesser/numpy,mattip/numpy,shoyer/numpy,solarjoe/numpy,pizzathief/numpy,mhvk/numpy,pbrod/numpy,jorisvandenbossche/numpy,MSeifert04/numpy,charris/numpy,anntzer/numpy,seberg/numpy,bringingheavendown/numpy,numpy/numpy,shoyer/numpy,madphysicist/numpy,numpy/numpy,pizzathief/numpy,jakirkham/numpy,ContinuumIO/numpy,jorisvandenbossche/numpy,pizzathief/numpy,simongibbons/numpy,numpy/numpy,Eric89GXL/numpy,chatcannon/numpy,jakirkham/numpy,simongibbons/numpy,WarrenWeckesser/numpy,grlee77/numpy,seberg/numpy,utke1/numpy,mhvk/numpy,behzadnouri/numpy,bertrand-l/numpy,madphysicist/numpy,grlee77/numpy,chatcannon/numpy,WarrenWeckesser/numpy,abalkin/numpy,simongibbons/numpy,behzadnouri/numpy