sdbus_mock: Make get_mocked_new() inline

Make get_mocked_new() inline so different tests can be linked together.
Otherwise, the build gets multiple definition of this function, if
different cases are linked together.

Tested: Link test cases using this function OK.

Change-Id: Ifa1c62f9615ba0847b49eb73e9b977a865909bb2
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/sdbusplus/test/sdbus_mock.hpp b/sdbusplus/test/sdbus_mock.hpp
index 6fe9cb7..6939630 100644
--- a/sdbusplus/test/sdbus_mock.hpp
+++ b/sdbusplus/test/sdbus_mock.hpp
@@ -102,7 +102,7 @@
     MOCK_METHOD2(sd_bus_wait, int(sd_bus *, uint64_t));
 };
 
-bus::bus get_mocked_new(SdBusMock *sdbus)
+inline bus::bus get_mocked_new(SdBusMock *sdbus)
 {
     using ::testing::IsNull;
     using ::testing::Return;