[PATCH 04/10] staging: comedi: make some variables unsigned in comedi_read()

In `comedi_read()`, the `n` and `m` variables are of type `int`. Change them to `unsigned int` as they are used to measure a positive number of bytes. The `count` variable is also of type `int` and holds the returned number of bytes. Change it to type `ssize_t` to match the function's return

[PATCH 04/10] staging: comedi: make some variables unsigned in comedi_read()

In `comedi_read()`, the `n` and `m` variables are of type `int`. Change them to `unsigned int` as they are used to measure a positive number of bytes. The `count` variable is also of type `int` and holds the returned number of bytes. Change it to type `ssize_t` to match the function's return