Return value of a function 'rte_zmalloc' is dereferenced without
checking, and it may call segmentation fault.

This patch fixed it.

Fixes: f8be1786b1b8 ("app/crypto-perf: introduce performance test
application")
Cc: stable@dpdk.org

Signed-off-by: Min Hu (Connor) <redacted>
---
v2:
* fix compiling warning.

Please fix the compilation reported by CI
In file included from ../lib/eal/include/rte_bus.h:24:0,
                 from ../lib/eal/include/rte_eal.h:21,
                 from ../lib/eal/include/rte_lcore.h:16,
                 from ../lib/eal/include/generic/rte_spinlock.h:21,
                 from ../lib/eal/x86/include/rte_spinlock.h:12,
                 from ../lib/mempool/rte_mempool.h:44,
                 from ../lib/mbuf/rte_mbuf.h:38,
                 from ../lib/cryptodev/rte_crypto.h:20,
                 from ../lib/cryptodev/rte_cryptodev.h:22,
                 from ../app/test-crypto-perf/cperf_options_parsing.c:8:
../app/test-crypto-perf/cperf_options_parsing.c: In function ‘parse_test_name’:
../app/test-crypto-perf/cperf_options_parsing.c:511:19: error: format ‘%u’ expects argument of type ‘unsigned int’, but argument 4 has type ‘size_t {aka long unsigned int}’ [-Werror=format=]
    strlen(arg) + 3);
    ~~~~~~~~~~~~~~~^
../lib/eal/include/rte_log.h:348:25: note: in definition of macro ‘RTE_LOG’
    RTE_LOGTYPE_ ## t, # t ": " __VA_ARGS__)