Remove some white space at EOL.

Remove some white space at EOL.

Protect a setmode call with INT{ON,OFF} as it calls malloc internally.

Fix the error message if the mask that is passed to umask -S contains
non-digits.

Remove dead code.  Inspection of the control and data flow showed that
variable "backslash" is always false (0) when the "if"-expression is
evaluated, hence the whole block is effectively dead code.
Additionally, the skipping of characters after a backslash is already
performed correctly a few lines above, so this code is also not
needed at all.

- Don't use quad_t when we really mean rlim_t.
- Cast rlim_t to intmax_t when printing it.

Callers of error() don't need to supply a program name prefix in the
error message. Stops ulimit giving error messages like "ulimit: ulimit: xyz".

Obtained-from:  FreeBSD