psu-ng: Fix failing CI tests due to IBM_VPD

When c12c53b985b9ac12c3c83df47371e7c2c70ae21b merged, the CI tests for
the phosphor-power repository started intermittently failing.

The expected calls for updateInventory() do not apply if the
ibm-vpd=false, which is the default.

Add #if IBM_VPD check around test calls that are only expected if that
is enabled.

Tested:
     x86sdk
       $ meson --reconfigure ... -Dibm-vpd=false ... x86build
       $ ninja -C x86build
       $ ./x86build/phosphor-power-supply/test/phosphor-power-supply-tests
       Verify no tests FAILED.
     x86sdk
       $ meson --reconfigure ... -Dibm-vpd=true ... x86build
       $ ninja -C x86build
       $ ./x86build/phosphor-power-supply/test/phosphor-power-supply-tests
       Verify no tests FAILED.
     Run openbmc-build-scripts/scripts/build-unit-test-docker
       Verify SUCCESS.

See:
    https://gerrit.openbmc-project.xyz/c/openbmc/openbmc-build-scripts/+/42141
      (Fix for meson problem in CI)
    https://github.com/openbmc/docs/blob/master/testing/local-ci-build.md
      (How to run local CI)

Signed-off-by: Brandon Wyman <bjwyman@gmail.com>
Change-Id: I4d481d7a493157b298e28d87cb2d962a8bdf5ccf
diff --git a/phosphor-power-supply/test/power_supply_tests.cpp b/phosphor-power-supply/test/power_supply_tests.cpp
index b028d56..74d98c1 100644
--- a/phosphor-power-supply/test/power_supply_tests.cpp
+++ b/phosphor-power-supply/test/power_supply_tests.cpp
@@ -286,6 +286,7 @@
         EXPECT_CALL(mockPMBus, readString(_, _)).WillRepeatedly(Return(""));
         psu.updateInventory();
 
+#if IBM_VPD
         EXPECT_CALL(mockPMBus, readString(_, _))
             .WillOnce(Return("CCIN"))
             .WillOnce(Return("PN3456"))
@@ -293,6 +294,7 @@
             .WillOnce(Return("HEADER"))
             .WillOnce(Return("SN3456"))
             .WillOnce(Return("FW3456"));
+#endif
         psu.updateInventory();
         // TODO: D-Bus mocking to verify values stored on D-Bus (???)
     }