libprocinfo: Update ParseMapsFileLine comments for char *p parameter. am: 6950ce0468

Original change: https://android-review.googlesource.com/c/platform/system/libprocinfo/+/2163805

Change-Id: I5ac6638736ddc23ad80979885145da4e7ca59929
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>