[trusty] Remove unused FallibleVec import

Background:
After properly namespacing the dependencies of the service_dispatcher!
macro, there are some usused imports that should be removed

New Stuff:
* Removed an import of FallibleVec

Bug: 312749603

Change-Id: Iafc21762659ce0174a07d22c7fc256f7039a8bf6
Signed-off-by: Ross Kettleson <kettro@google.com>
1 file changed