icmap: fix a valgrind errors (pass 1)

clean up a lot of allocated blocks at exit.
those changes has no runtime effects, but it makes valgrind
output a bit more useful by dropping over 700 errors/warnings to skip
over every single run.

there are still a few icmap related valgrind errors but those need
some more complex and timeconsuming investigation.

pre patch:

21844== HEAP SUMMARY:

21844== in use at exit: 1,229,321 bytes in 1,516 blocks

21844== total heap usage: 7,191 allocs, 5,675 frees, 3,819,853 bytes allocated

21844== LEAK SUMMARY:

21844== definitely lost: 3,617 bytes in 11 blocks

21844== indirectly lost: 21,960 bytes in 11 blocks

21844== possibly lost: 1,080,101 bytes in 131 blocks

21844== still reachable: 123,643 bytes in 1,363 blocks

21844== suppressed: 0 bytes in 0 blocks

21844== ERROR SUMMARY: 136 errors from 136 contexts (suppressed: 0 from 0)

post patch:

25793== HEAP SUMMARY:

25793== in use at exit: 1,185,870 bytes in 808 blocks

25793== total heap usage: 9,427 allocs, 8,619 frees, 4,156,841 bytes allocated

25793== LEAK SUMMARY:

25793== definitely lost: 3,697 bytes in 12 blocks

25793== indirectly lost: 22,248 bytes in 13 blocks

25793== possibly lost: 1,079,655 bytes in 113 blocks

25793== still reachable: 80,270 bytes in 670 blocks

25793== suppressed: 0 bytes in 0 blocks

25793== ERROR SUMMARY: 119 errors from 119 contexts (suppressed: 0 from 0)

Signed-off-by: Fabio M. Di Nitto <fdinitto@redhat.com>
Reviewed-by: Jan Friesse <jfriesse@redhat.com>