* Coverity: Resource leak

Fix some resource leak.

(cherry picked from commit e27ec070)

* Coverity: Identical code for different branches

Clean identical code in heap.c and analyze.c

(cherry picked from commit f076205c)

* Coverity: Variable unused

Remove unused varaible.
For tuplesort.h, we doesn't support mksort based cluster,
so we should just set is_mk_tuplesortstate to false

(cherry picked from commit e5c86775)

* Coverity: Logically dead code

Remove dead code.
insertDesc is alwasy NULL in ao_vacuum_rel_compact()

(cherry picked from commit 38552bf7)

* Coverity: Sizeof not portable

sizeof(HeapTuple *) should be sizeof(HeapTuple)

(cherry picked from commit cf23db49)

* Coverity: Behave test misformat

conn = dbconn.connect() should be aligned with if statement, or it
will never be executed.

(cherry picked from commit 126ba1c6)

* Coverity: Check return value of strcmp

return value of strcmp is not checked in some branches.

(cherry picked from commit fd498cf9)