rbd-replay: Fix compiler warning in unit tests

Was getting:
test/test_rbd_replay.cc:44:3: warning: converting ‘false’ to pointer type for argument 1 of ‘char testing::internal::IsNullLiteralHelper(testing::internal::Secret*)’ [-Wconversion-null]

Fixed by changing EXPECT_EQ(false, xxx) to EXPECT_FALSE(xxx).
For completeness, also changed EXPECT_EQ(true, xxx) to EXPECT_TRUE(xxx).

Signed-off-by: Adam Crume <adamcrume@gmail.com>