taskset: independent of hardcoded NR_CPUS max.

taskset: independent of hardcoded NR_CPUS max.

This patch makes the taskset command independent of the system's maximum
number of cpus (CONFIG_NR_CPUS).  The maximum for CONFIG_NR_CPUS is a
moving target.

With this patch the size of the systems's cpumask_t is gotten from
sched_getaffinity(2).

This patch uses variable length bitmasks borrowed from Paul Jackson's
variable size bitmask routines (hence I kept his copyright notice).
This replaces the use of the glibc CPU_SETSIZE, CPU_SET, CPU_ZERO and
CPU_ISSET macros which depend on a hardcoded size for cpu_set_t.

(also fixes one little nit: the -V option is "-v" in the built-in help, so
 changed the built-in help)

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Signed-off-by: Karel Zak <kzak@redhat.com>