Fix BruteForce test trying to validate empty memories

This test was complaining if the driver refused to validate a memory
it returned. However, it was trying to validate empty memories,
which while those should be consistent, isn't really what the test
was trying to enforce. So, skip memories that are empty there.

tests/driver_xfails.yaml

@@ -13,50 +13,14 @@ BTECH_GMRS-20V2:
   - class: TestCaseBruteForce
     test: test_validate_all
     reason: Improper application of the duplex policy
-BTECH_GMRS-V2:
-  - class: TestCaseBruteForce
-    test: test_validate_all
-    reason: Improper application of the duplex policy
-BTECH_GMRS-50X1:
-  - class: TestCaseBruteForce
-    test: test_validate_all
-    reason: Improper application of the duplex policy
 BTECH_GMRS-50V2:
   - class: TestCaseBruteForce
     test: test_validate_all
     reason: Improper application of the duplex policy
-BTECH_MURS-V2:
-  - class: TestCaseBruteForce
-    test: test_validate_all
-    reason: Improper application of the duplex policy
 Abbree_AR-730:
   - class: TestCaseBruteForce
     test: test_validate_all
     reason: Broken name stored in memory 256?
-Radtel_RT-730:
-  - class: TestCaseBruteForce
-    test: test_validate_all
-    reason: Improper application of the duplex policy
-Retevis_RB17P:
-  - class: TestCaseBruteForce
-    test: test_validate_all
-    reason: Improper application of the duplex policy
-TIDRADIO_TD-H3:
-  - class: TestCaseBruteForce
-    test: test_validate_all
-    reason: Memory 3 stored with TX outside TX range
-TIDRADIO_TD-H8:
-  - class: TestCaseBruteForce
-    test: test_validate_all
-    reason: Memory 6 stored with TX outside TX range
-TIDRADIO_TD-H8-GMRS:
-  - class: TestCaseBruteForce
-    test: test_validate_all
-    reason: Memory 31 stored with TX outside gmrs bands
-TIDRADIO_TD-H8-HAM:
-  - class: TestCaseBruteForce
-    test: test_validate_all
-    reason: Memory 31 stored with TX outside ham bands
 Yaesu_FT-90:
   - class: TestCaseBruteForce
     test: test_validate_all

tests/test_brute_force.py

@@ -197,11 +197,13 @@ class TestCaseBruteForce(base.DriverTest):
         lo, hi = self.rf.memory_bounds
         for i in range(lo, hi + 1):
             m1 = self.radio.get_memory(i)
+            if m1.empty:
+                continue
             errs, warns = chirp_common.split_validation_msgs(
                 self.radio.validate_memory(m1))
             self.assertEqual([], errs,
                              ('Radio has validation errors for memory %i '
-                              'stored in sample image') % i)
+                              'stored in sample image: %s') % (i, m1))
 
     @base.requires_feature('has_nostep_tuning', equal=False)
     def test_validate_all_steps(self):