common/rc: report kmemleak errors

If kmemleak is enabled, scan and report memory leaks after every
test.

Note that the kmemleak check support is EXPERIMENTAL! Due to the way
kmemleak works, the leak might be from an earlier test, or something
totally unrelated.

[eguan: add EXPERIMENTAL disclaimer in commit log too]

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

check

@@ -499,6 +499,7 @@ _expunge_test()
 	return 0
 }
 
+_init_kmemleak
 _prepare_test_list
 
 if $OPTIONS_HAVE_SECTIONS; then
@@ -791,6 +792,7 @@ for section in $HOST_OPTIONS_SECTIONS; do
 		    n_try=`expr $n_try + 1`
 		    _check_filesystems
 		    _check_dmesg || err=true
+		    _check_kmemleak || err=true
 		fi
 
 	    fi