tools/power turbostat: Fix gcc build warnings

Warning: ‘__builtin_strncpy’ specified bound 20 equals destination size
	[-Wstringop-truncation]

reduce param to strncpy, to guarantee that a null byte is always copied
into destination buffer.
Signed-off-by: NLen Brown <len.brown@intel.com>

tools/power/x86/turbostat/turbostat.c

@@ -5325,9 +5325,9 @@ int add_counter(unsigned int msr_num, char *path, char *name,
 	}
 
 	msrp->msr_num = msr_num;
-	strncpy(msrp->name, name, NAME_BYTES);
+	strncpy(msrp->name, name, NAME_BYTES - 1);
 	if (path)
-		strncpy(msrp->path, path, PATH_BYTES);
+		strncpy(msrp->path, path, PATH_BYTES - 1);
 	msrp->width = width;
 	msrp->type = type;
 	msrp->format = format;