selftests/resctrl: Fix incorrect parsing of option "-t"

selftests/resctrl: Fix incorrect parsing of option "-t"

Resctrl test suite accepts command line argument "-t" to specify the
unit tests to run in the test list (e.g., -t mbm,mba,cmt,cat) as
documented in the help.

When calling strtok() to parse the option, the incorrect delimiters
argument ":\t" is used. As a result, passing "-t mbm,mba,cmt,cat" throws
an invalid option error.

Fix this by using delimiters argument "," instead of ":\t" for parsing
of unit tests list. At the same time, remove the unnecessary "spaces"
between the unit tests in help documentation to prevent confusion.

Fixes: 790bf585b0ee ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest")
Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Fixes: 034c7678dd2c ("selftests/resctrl: Add README for resctrl tests")
Cc: stable@vger.kernel.org
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>