memory leak in pc_patch_compress

[achidlow]

Found a leak by running valgrind on my python unit tests.

It's because pc_patch_free is what frees the PCSTATS but pc_patch_dimensional_free is called instead.

==25371== 114 (72 direct, 42 indirect) bytes in 1 blocks are definitely lost in loss record 618 of 1,663
==25371==    at 0x4C29C0F: malloc (vg_replace_malloc.c:299)
==25371==    by 0x154CF34A: default_allocator (pc_mem.c:40)
==25371==    by 0x154CF5EE: pcalloc (pc_mem.c:136)
==25371==    by 0x154D4DBD: pc_stats_clone (pc_stats.c:133)
==25371==    by 0x154D08DF: pc_patch_dimensional_from_uncompressed (pc_patch_dimensional.c:87)
==25371==    by 0x154CFBBF: pc_patch_compress (pc_patch.c:142)
==25371==    by 0x154B0C0E: __pyx_pf_4pgpc_7PcPatch_10compressed (pgpc.c:7595)
==25371==    by 0x154B0C0E: __pyx_pw_4pgpc_7PcPatch_11compressed (pgpc.c:7574)
==25371==    by 0x53EE15: PyEval_EvalFrameEx (in /usr/bin/python3.5)
<snipped>
==25371==    by 0x5C3676: PyObject_Call (in /usr/bin/python3.5)
==25371==    by 0x4DEB5D: ??? (in /usr/bin/python3.5)