controller: Fix "use after free" issue in statctrl_run(). #3240

Job	Run time
osx clang --disable-ssl	2m 20s
linux rpm fedora	7m 25s
Prepare container	2m 21s
dpdk gcc	2m 23s
linux gcc --disable-ssl	2m 17s
linux clang --disable-ssl	2m 28s
linux gcc test -500	14m 19s
linux gcc test 501-1000	10m 31s
linux gcc test 1001-	5m 45s
linux clang test sanitizers -300	11m 21s
linux clang test sanitizers 301-600	14m 19s
linux clang test sanitizers 601-900	9m 24s
linux clang test sanitizers 901-1200	7m 30s
linux clang test sanitizers 1201-	7m 10s
linux gcc test -ljemalloc -500	14m 38s
linux gcc test -ljemalloc 501-1000	10m 37s
linux gcc test -ljemalloc 1001-	5m 51s
linux gcc system-test-dpdk dpdk -100	10m 52s
linux gcc system-test-dpdk dpdk 101-200	17m 47s
linux gcc system-test-dpdk dpdk 201-	19m 14s
linux gcc system-test-userspace -100	9m 47s
linux gcc system-test-userspace 101-200	16m 10s
linux gcc system-test-userspace 201-	17m 46s
linux gcc system-test -100	12m 41s
linux gcc system-test 101-200	18m 25s
linux gcc system-test 201-	24m 27s
linux clang system-test sanitizers -100	14m 43s
linux clang system-test sanitizers 101-200	20m 17s
linux clang system-test sanitizers 201-	26m 34s
linux x86 gcc --disable-ssl	2m 15s
	5h 41m 37s

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