Change the working dir of the printf conformance test as it wants to create a temporary file name called 'tmp' in CWD.
Change the working dir of the printf conformance test as it wants to
create a temporary file name called 'tmp' in CWD.

At least for me, in build/examples/conformance there is a directory
called 'tmp', thus it failed to create the file.

pocl/pocl,Oblomov/pocl,Oblomov/pocl,pocl/pocl,Oblomov/pocl,franz/pocl,Oblomov/pocl,pocl/pocl,franz/pocl,franz/pocl,pocl/pocl,franz/pocl,franz/pocl,Oblomov/pocl,pocl/pocl