[PATCH v2] app/testpmd: fix dereference before null check

[Sean Morrissey <sean.morrissey@intel.com>]

Assign 'left' variable only after null check on 'size'
as function returns if 'size' is null.

Coverity issue: 374381
Fixes: 169a9fed1f4 ("app/testpmd: fix hex string parser support for flow API")
Cc: stable@dpdk.org
Cc: wei.zhao1@intel.com

Signed-off-by: Sean Morrissey <sean.morrissey@intel.com>

Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
 app/test-pmd/cmdline_flow.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/app/test-pmd/cmdline_flow.c b/app/test-pmd/cmdline_flow.c
index 5c2bba48ad..bbaf18d76e 100644
--- a/app/test-pmd/cmdline_flow.c
+++ b/app/test-pmd/cmdline_flow.c
@@ -7702,8 +7702,8 @@ parse_string(struct context *ctx, const struct token *token,
 static int
 parse_hex_string(const char *src, uint8_t *dst, uint32_t *size)
 {
-	uint32_t left = *size;
 	const uint8_t *head = dst;
+	uint32_t left;
 
 	/* Check input parameters */
 	if ((src == NULL) ||
@@ -7712,6 +7712,8 @@ parse_hex_string(const char *src, uint8_t *dst, uint32_t *size)
 		(*size == 0))
 		return -1;
 
+	left = *size;
+
 	/* Convert chars to bytes */
 	while (left) {
 		char tmp[3], *end = tmp;
-- 
2.25.1