Don't wrap mmap() at all for dynamic linking (i.e., the LD_PRELOAD use case). There is no way for Darshan to safely intercept mmap() when used with hugepages on recent Cray XC platforms because of a deadlock in dlsym() when used in that call path.

Closes #223 (closed)

@csimarro, you are welcome to test this branch if you get a chance; we'll be rolling it out in the 3.1.3 release.