x86: kernel/dumpstack.c simple_strtoul cleanup

Change kstack_setup() and code_bytes_setup() in kernel/dumpstack.c
to call kstrtoul() instead of calling obsoleted simple_strtoul().

Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Link: http://lkml.kernel.org/r/1336327084.2897.15.camel@lorien2


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>