Thread safety issue if two clfftBakePlan() calls, on different objects, execute concurrently

[azonenberg]

Using latest clfft binary packages for Debian, I get an assertion failure:

glscopeclient: /build/clfft-8xRwfG/clfft-2.12.2/src/library/repo.cpp:217:
clfftStatus FFTRepo::setclProgram(clfftGenerators, const FFTKernelSignatureHeader*, _cl_program* const&,
_cl_device_id* const&, _cl_context* const&): Assertion `NULL == p' failed.

Adding mutexes to serialize the bake operations eliminates the assertion. I have to date not seen any issues with concurrent execution of FFTs issued from different threads, only the bake operation.