gluterd: fix memory leak in glusterd

[chen1195585098]

In glusterd-store.c, there are while loops like:

gf_store_iter_get_next(iter, &key, &value, &op_errno); 
while (!ret) {
    if (xx_condition) {
        do_something();
        goto out;
    }
    GF_FREE(key);
    GF_FREE(value);
    key = NULL;
    value = NULL;

    ret = gf_store_iter_get_next(iter, &key, &value, &op_errno);

}

It's ok in normal case, howerver, once the condition does not meet and the procedure goto 'out', there will be memory leak.

Hence, it is necessary to put a check at 'out'.

Similar leaks will be triggered in glusterd_store_retrieve_peers. If no peerinfo is found, the procedure will goto the next loop. It means memory allocated for key & value will be leaked once gf_store_iter_get_next is called again in the next loop.

This patch fixes above mentioned memory leaks, and that detected by asan.

Direct leak of 11430 byte(s) in 150 object(s) allocated from:
    #0 0x7f59844efbb8 in __interceptor_malloc (/lib64/libasan.so.5+0xefbb8)
    #1 0x7f5983aeb96d in __gf_malloc (/lib64/libglusterfs.so.0+0xeb96d)
    #2 0x7f59775b569b in glusterd_store_update_volinfo ../../../../libglusterfs/src/glusterfs/mem-pool.h:170
    #3 0x7f59775be3b5 in glusterd_store_retrieve_volume glusterd-store.c:3334
    #4 0x7f59775bf076 in glusterd_store_retrieve_volumes glusterd-store.c:3571
    #5 0x7f59775bfc9e in glusterd_restore glusterd-store.c:4913
    #6 0x7f59774ca5a1  (/usr/lib64/glusterfs/8.2/xlator/mgmt/glusterd.so+0xca5a1)
    #7 0x7f5983a7cb6b in __xlator_init xlator.c:594
    #8 0x7f5983b0c5d0 in glusterfs_graph_init graph.c:422
    #9 0x7f5983b0d422 in glusterfs_graph_activate (/lib64/libglusterfs.so.0+0x10d422)
    #10 0x5605f2e1eff5 in glusterfs_process_volfp glusterfsd.c:2506
    #11 0x5605f2e1f238 in glusterfs_volumes_init glusterfsd.c:2577
    #12 0x5605f2e15d8d in main (/usr/sbin/glusterfsd+0x15d8d)
    #13 0x7f598103acf2 in __libc_start_main (/lib64/libc.so.6+0x3acf2)
    #14 0x5605f2e162cd in _start (/usr/sbin/glusterfsd+0x162cd)

Direct leak of 3351 byte(s) in 30 object(s) allocated from:
    #0 0x7f59844efbb8 in __interceptor_malloc (/lib64/libasan.so.5+0xefbb8)
    #1 0x7f5983aeb96d in __gf_malloc (/lib64/libglusterfs.so.0+0xeb96d)
    #2 0x7f59775541e7 in glusterd_is_path_in_use ../../../../libglusterfs/src/glusterfs/mem-pool.h:170
    #3 0x7f59775541e7 in glusterd_check_and_set_brick_xattr glusterd-utils.c:8203
    #4 0x7f5977554d7c in glusterd_validate_and_create_brickpath glusterd-utils.c:1549
    #5 0x7f5977645fcb in glusterd_op_stage_create_volume glusterd-volume-ops.c:1260
    #6 0x7f5977519025 in glusterd_op_stage_validate glusterd-op-sm.c:5787
    #7 0x7f5977672555 in gd_stage_op_phase glusterd-syncop.c:1297
    #8 0x7f5977676db0 in gd_sync_task_begin glusterd-syncop.c:1951
    #9 0x7f59776775dc in glusterd_op_begin_synctask glusterd-syncop.c:2016
    #10 0x7f5977642bd6 in __glusterd_handle_create_volume glusterd-volume-ops.c:506
    #11 0x7f59774e27b1 in glusterd_big_locked_handler glusterd-handler.c:83
    #12 0x7f5983b14cac in synctask_wrap syncop.c:353
    #13 0x7f59810240af  (/lib64/libc.so.6+0x240af)

Fixes: #4383