Fix a compilation warning in the ph test code.
Fix a compilation warning in the ph test code.

8l/jemalloc,AndroidExternal/jemalloc,wqfish/jemalloc,wqfish/jemalloc,glandium/jemalloc,glandium/jemalloc,jemalloc/jemalloc-cmake,wqfish/jemalloc,leebaok/jemalloc-4.2.1-readcode,jemalloc/jemalloc-cmake,8l/jemalloc,jemalloc/jemalloc-cmake,8l/jemalloc,leebaok/jemalloc-4.2.1-readcode,8l/jemalloc,AndroidExternal/jemalloc,AndroidExternal/jemalloc,glandium/jemalloc,leebaok/jemalloc-4.2.1-readcode,wqfish/jemalloc,glandium/jemalloc,wqfish/jemalloc,AndroidExternal/jemalloc,jemalloc/jemalloc-cmake,leebaok/jemalloc-4.2.1-readcode