Free job statistics from the migration cookie

==404== 232 bytes in 1 blocks are definitely lost in loss record 669 of 758
==404==    at 0x4C2B934: calloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==404==    by 0x52A2BF3: virAlloc (viralloc.c:144)
==404==    by 0x1D49AD70: qemuMigrationCookieAddStatistics (qemu_migration.c:554)
==404==    by 0x1D49AD70: qemuMigrationBakeCookie (qemu_migration.c:1228)
==404==    by 0x1D4A43B8: qemuMigrationFinish (qemu_migration.c:5002)
==404==    by 0x1D4C9339: qemuDomainMigrateFinish3Params (qemu_driver.c:11526)

Introduced by commit 5d6fb963

src/qemu/qemu_migration.c

@@ -219,6 +219,7 @@ static void qemuMigrationCookieFree(qemuMigrationCookiePtr mig)
     VIR_FREE(mig->lockState);
     VIR_FREE(mig->lockDriver);
     VIR_FREE(mig->nbd);
+    VIR_FREE(mig->jobInfo);
     VIR_FREE(mig);
 }