thermal_sys: remove obfuscating used-once macros

These don't add any value as they are used only once and the surrounding
code uses similar variable.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>