The CodingStyle document suggests programs should allow for
cmdlines of at least 128k. Only the ps program can display
such a cmdline, and only with multiple -w switches.
The library function file2strvec can essentially return
a cmdline of unlimited length. However, the library function
fill_cmdline_cvt used an arbitrary upper limit of 2048 for
buffers automatically allocated on the stack.
This patch raises the fill_cmdline_cvt upper limit to 128k via
dymaically acquired utility buffers ensured by the openproc
function.
It also makes indentation consistent in the openproc function.
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