Remove is_buck2() calls from folly/logging/test/TARGETS

Summary:
buck1 is declared dead, is_buck2() checks will always return true. We can statically eliminate
these calls and associated conditional checks. folly/logging/test/TARGETS was codemodded with libcst.

Reviewed By: Orvid

Differential Revision: D63296015

fbshipit-source-id: b3afaca61022f2504e402f118bd1c30975fc6a19

folly/logging/test/BUCK

@@ -2,7 +2,6 @@ load("@fbcode_macros//build_defs:cpp_binary.bzl", "cpp_binary")
 load("@fbcode_macros//build_defs:cpp_library.bzl", "cpp_library")
 load("@fbcode_macros//build_defs:cpp_unittest.bzl", "cpp_unittest")
 load("@fbcode_macros//build_defs:python_unittest.bzl", "python_unittest")
-load("@fbsource//tools/build_defs/buck2:is_buck2.bzl", "is_buck2")
 
 oncall("fbcode_entropy_wardens_folly")
 
@@ -326,7 +325,7 @@ cpp_unittest(
     name = "xlog_test",
     srcs = ["XlogTest.cpp"],
     preprocessor_flags = [
-        "-DFOLLY_XLOG_SUPPORT_BUCK2" if is_buck2() else "-DFOLLY_XLOG_SUPPORT_BUCK1",
+        "-DFOLLY_XLOG_SUPPORT_BUCK2",
     ],
     deps = [
         ":test_handler",