tools/power turbostat: Fix names matching

Fix the 'find_msrp_by_name()' function which returns incorrect matches for
cases like this:

s1 = "C1-";
find_msrp_by_name(head, s1);

Inside 'find_msrp_by_name()':
...
s2 = "C1"
if !(strcnmp(s1, s2, len(s2)))
	// Incorrect match!
	return mp;

Full strings should be match istead. Switch to 'strcmp()' to fix the problem.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>