layers: Don't confuse VkResult/VkBool32 in generators.

In some cases, the generator would return the special error for
validation failed for functions that return a VkBool32. Fix this, and
also some cases of initializing a VkBool32 with VkResult.

Change-Id: Icc071e647f293848d62a922d492ed41dfc5a4be1
diff --git a/scripts/parameter_validation_generator.py b/scripts/parameter_validation_generator.py
index 01ed1bb..9c673fc 100644
--- a/scripts/parameter_validation_generator.py
+++ b/scripts/parameter_validation_generator.py
@@ -1200,7 +1200,13 @@
                 cmdDef += '%sbool skip = false;\n' % indent
                 if not just_validate:
                     if command.result != '':
-                        cmdDef += indent + '%s result = VK_ERROR_VALIDATION_FAILED_EXT;\n' % command.result
+                        if command.result == "VkResult":
+                            cmdDef += indent + '%s result = VK_ERROR_VALIDATION_FAILED_EXT;\n' % command.result
+                        elif command.result == "VkBool32":
+                            cmdDef += indent + '%s result = VK_FALSE;\n' % command.result
+                        else:
+                            raise Exception("Unknown result type: " + command.result)
+
                     cmdDef += '%sstd::unique_lock<std::mutex> lock(global_lock);\n' % indent
                 for line in lines:
                     cmdDef += '\n'