Remove -Wno-error from system/extras

Fix warnings in memtrack and micro_bench and remove -Wno-error.

Test: mmma system/extras
Change-Id: I48261f6af94c7fcba8a10e8fb558f47ab9d0e8be
diff --git a/memtrack/memtrack.cpp b/memtrack/memtrack.cpp
index d373609..eaeecc3 100644
--- a/memtrack/memtrack.cpp
+++ b/memtrack/memtrack.cpp
@@ -68,7 +68,7 @@
   while (cur_idx_ + bytes_needed >= len_) {
     bytes = read(fd_, data_ + len_, max_ - len_);
     if (bytes == 0 || bytes == -1) {
-      read_complete_; // unused read?
+      read_complete_ = true;
       break;
     }
     len_ += bytes;