mod/dvfs/test: Fix uninitialised pointer issue in mod_dvfs unit test

Some unit tests in mod_dvfs_unit_test.c initialise local data structures with the minimum information required to test DVFS functions.

The local data structures sometimes have pointers in them that depending on the particular test being run - should also be initialised, but in some cases the unit test failed to do that.

This resulted in some pointers being initialised with whatever random data was on the stack and depending on what ended in those pointers, accessing data fields through them could end in a segfault.

The fix makes sure all pointers that need initialising are properly set.

Signed-off-by: Francesco Rosati francesco.rosati@arm.com