postProcessEntryPoints: return after setIgnored and setSimple are set

Summary:
This patch fixes the assertion failure during instrumentation.

The assertion is raised by `getInstructionAtOffset` , which expects `CurrentState` to be either `Disassembled` or `CFG`.

The function is called from `postProcessEntryPoints`, which goes over Labels and performs a series of checks. The checks call BinaryFunction methods `setSimple(false)` or `setIgnored()`.
However, if `setIgnored` is invoked, it resets the state to `Empty`. Thus subsequent call to `getInstructionAtOffset` will fail.

(cherry picked from FBD24005197)