Only 2 `openmp` testsuite failures remain on Solaris/amd64. They are due the same issue: the tests in question assume `NULL` pointers to be printed as `(nil)` while the rest of the testsuite uses `[[NULL]]` for that. This patch changes them to follow suit. Tested on `amd64-pc-solaris2.11` and `x86_64-pc-linux-gnu`.