Log when trying to profile non profilable app.

Change-Id: I91b489d3ff78ab7153ae1a7854ae448e87a6e8da
diff --git a/libc/bionic/malloc_heapprofd.cpp b/libc/bionic/malloc_heapprofd.cpp
index 5d3735d..d0117f3 100644
--- a/libc/bionic/malloc_heapprofd.cpp
+++ b/libc/bionic/malloc_heapprofd.cpp
@@ -116,6 +116,7 @@
   // Zygote child processes must be marked profileable.
   if (gZygoteChild &&
       !atomic_load_explicit(&gZygoteChildProfileable, memory_order_acquire)) {
+    error_log("%s: not enabling heapprofd, not marked profileable.", getprogname());
     return;
   }