cpumask: cpulist_parse() comments correction

As introduced in Rusty's commit 29c0177e, the function has no
parameter @len, so need to remove it from comments to avoid kernel-doc
warning:

alexs@debian:~/linux-next$ scripts/kernel-doc -man
include/linux/cpumask.h | split-man.pl /tmp/man
....
Warning(include/linux/cpumask.h:602): Excess function parameter 'len'
description in 'cpulist_parse'

and correct the function name in comments to cpulist_parse.
Signed-off-by: NAlex Shi <alex.shi@intel.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

include/linux/cpumask.h

@@ -591,9 +591,8 @@ static inline int cpulist_scnprintf(char *buf, int len,
 }
 
 /**
- * cpulist_parse_user - extract a cpumask from a user string of ranges
+ * cpulist_parse - extract a cpumask from a user string of ranges
  * @buf: the buffer to extract from
- * @len: the length of the buffer
  * @dstp: the cpumask to set.
  *
  * Returns -errno, or 0 for success.