thermal: always use curly brackets when dereferencing array elements

${array[1]} is the recommended way to dereference array elements in
bash.  While $array[1] may work with some implementations of bash, it
is not guaranteed to work.

Signed-off-by: Javi Merino <javi.merino@arm.com>
Acked-by: Sanjay Singh Rawat <sanjay.rawat@linaro.org>
1 file changed