Use double bracket conditional compound command

Odd failures in the read the docs jobs
casued by not quoting "$result"

Im going to quote it and switch to double bracket.
Fixed the issue in my testing.

Errors seen were:
jq: error (at <stdin>:1): Cannot index string with string "success"
./script: line 11: [: ==: unary operator expected

Signed-off-by: Aric Gardner <agardner@linuxfoundation.org>
Change-Id: Ic7554ddfa384b817ad3aac311972e6cfc52e0b49