SM crashes on VLArray

QA encountered an SM crash investigation led to trace leading to changes for using VLArray to fix warnings.

Process 3230 (StorageManager) of user 991 dumped core.
Stack trace of thread 3251:
#0 0x00007f9661a9470f raise (libc.so.6)
#1 0x00007f9661a7eb25 abort (libc.so.6)
#2 0x00007f9661a7e9f9 __assert_fail_base.cold.0 (libc.so.6)
#3 0x00007f9661a8ccc6 __assert_fail (libc.so.6)
#4 0x00007f96635fb68b _ZN14storagemanager12ScopedCloserC1Ei (libstoragemanager.so)
#5 0x00007f96635b9157 _ZN14storagemanager13IOCoordinator4readEPKcPhlm (libstoragemanager.so)
#6 0x00007f96635aacb6 _ZN14storagemanager8ReadTask3runEv (libstoragemanager.so)
#7 0x00007f96635aa8e1 _ZN14storagemanager11ProcessTaskclEv (libstoragemanager.so)
#8 0x00007f96635adb95 _ZN14storagemanager10ThreadPool15_processingLoopERN5boost11unique_lockINS1_5mutexEEE (libstoragemanager.so)
#9 0x00007f96635adfd4 _ZN14storagemanager10ThreadPool14processingLoopEv (libstoragemanager.so)
#10 0x00007f9662f22581 thread_proxy (libboost_thread.so.1.66.0)
#11 0x00007f96638512de start_thread (libpthread.so.0)
#12 0x00007f9661b58e83 __clone (libc.so.6)