fs: fix readFileSync("/proc/cpuinfo") regression
fs: fix readFileSync("/proc/cpuinfo") regression

Don't use positional reads. Not all proc files support pread(), especially on
older linux kernels.

Fixes #3808.

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node