VED-843: Refactor validator methods (#1090)

Author: JamesW1-NHS

lambdas/shared/src/common/models/fhir_immunization_pre_validators.py

@@ -230,7 +230,7 @@ def pre_validate_practitioner_reference(self, values: dict) -> None:
         practitioner_id = str(practitioner[0]["id"])
 
         # Ensure that there are no internal references other than to the contained practitioner
-        if sum(1 for x in performer_internal_references if x != "#" + practitioner_id) != 0:
+        if any(x != "#" + practitioner_id for x in performer_internal_references):
             raise ValueError(
                 "performer must not contain any internal references other than"
                 + " to the contained Practitioner resource"
@@ -882,8 +882,6 @@ def pre_validate_dose_quantity_system_and_code(self, values: dict) -> None:
 
         PreValidation.require_system_when_code_present(code, system, "doseQuantity.code", "doseQuantity.system")
 
-        return values
-
     def pre_validate_dose_quantity_unit(self, values: dict) -> None:
         """
         Pre-validate that, if doseQuantity.unit (legacy CSV field name: DOSE_UNIT_TERM) exists,