docs(requestcontrol): correct FlowControlAdmissionController.Admit docstring

The docstring for FlowControlAdmissionController.Admit previously claimed
that it checked for saturation on sheddable requests first, then deferred
to Flow Control. This was incorrect; the implementation only defers via
EnqueueAndWait, and saturation shedding is handled downstream by the
dispatch cycle.

Update the docstring to accurately describe the implemented behavior.
No runtime changes are made.

Fixes llm-d#1934

Signed-off-by: ChethanUK <chethanuk@outlook.com>

Author: chethanuk

pkg/epp/requestcontrol/admission.go

@@ -145,8 +145,8 @@ func NewFlowControlAdmissionController(fc flowController, poolName string) *Flow
 	}
 }
 
-// Admit implements the AdmissionController interface by checking for saturation on sheddable requests first, then
-// deferring to the Flow Control system.
+// Admit defers the admission decision to the Flow Control system via EnqueueAndWait; saturation-based shedding
+// of sheddable requests is handled downstream by the dispatch cycle, not at admission.
 func (fcac *FlowControlAdmissionController) Admit(
 	ctx context.Context,
 	reqCtx *handlers.RequestContext,