build: fix linker error in BloomFileTestBase
build: fix linker error in BloomFileTestBase

I saw this when building on macOS:

[241/562] Linking CXX shared library lib/libcfile_test_util.dylib
FAILED: lib/libcfile_test_util.dylib
: && /Applications/Xcode.app/Contents/Developer/usr/bin/g++ -msse4.2 -Wall -Wno-sign-compare -Wno-comment -pthread -fno-strict-aliasing -DBOOST_DATE_TIME_POSIX_TIME_STD_CONFIG  -ggdb -Qunused-arguments -Wno-ambiguous-member-template -Wdocumentation-depre
cated-sync -Wno-unknown-warning-option -Wno-address-of-packed-member -std=c++11 -fsized-deallocation -g -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -dynamiclib -Wl,-headerpad_max_install_n
ames  -o lib/libcfile_test_util.dylib -install_name @rpath/libcfile_test_util.dylib src/kudu/cfile/CMakeFiles/cfile_test_util.dir/bloomfile-test-base.cc.o  -Wl,-rpath,/Users/awong/Repositories/kudu/build/debug/lib -Wl,-rpath,/Users/awong/Repositories/kud
u/thirdparty/installed/uninstrumented/lib  lib/libcfile.dylib  lib/libkudu_common.dylib  lib/libwire_protocol_proto.dylib  lib/libconsensus_metadata_proto.dylib  lib/libkudu_fs.dylib  lib/libfs_proto.dylib  lib/libkudu_util_compression.dylib  lib/libkudu_util.dylib  ../../thirdparty/installed/uninstrumented/lib/libcrcutil.dylib  ../../thirdparty/installed/uninstrumented/lib/libgflags.dylib  lib/libhistogram_proto.dylib  ../../thirdparty/installed/uninstrumented/lib/libev.dylib  lib/libmaintenance_manage
r_proto.dylib  lib/libmem_tracker_proto.dylib  lib/libversion_info_proto.dylib  ../../thirdparty/installed/uninstrumented/lib/libyaml-cpp.dylib  ../../thirdparty/installed/uninstrumented/lib/libtcmalloc.dylib  ../../thirdparty/installed/uninstrumented/li
b/libz.dylib  ../../thirdparty/installed/uninstrumented/lib/liblz4.a  ../../thirdparty/installed/uninstrumented/lib/libsnappy.dylib  lib/libgutil.dylib  ../../thirdparty/installed/uninstrumented/lib/libglog.dylib  lib/libcfile_proto.dylib  lib/libkudu_co
mmon_proto.dylib  lib/libblock_bloom_filter_proto.dylib  lib/libhash_proto.dylib  lib/libutil_compression_proto.dylib  lib/libpb_util_proto.dylib  ../../thirdparty/installed/uninstrumented/lib/libprotobuf.dylib  ../../thirdparty/installed/uninstrumented/
lib/bitshuffle.a && :
Undefined symbols for architecture x86_64:
  "kudu::KuduTest::SetUp()", referenced from:
      kudu::cfile::BloomFileTestBase::SetUp() in bloomfile-test-base.cc.o
  "testing::AssertionResult::AssertionResult(testing::AssertionResult const&)", referenced from:
...

Not sure why this wasn't caught in other builds, but the fix is easy
enough.

Change-Id: I0c4c9506a4afe2476e9adffa5372b7f56bf56199
Reviewed-on: http://gerrit.cloudera.org:8080/15459
Reviewed-by: Alexey Serbin <864f6b82bd94e8dda64141d4274519ee66e0102e@cloudera.com>
Tested-by: Alexey Serbin <864f6b82bd94e8dda64141d4274519ee66e0102e@cloudera.com>
Reviewed-by: Adar Dembo <866ca730bfc7f544e3ebce604ceeba4879f23df0@cloudera.com>

helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu,helifu/kudu