net/softnic: fix file descriptor leak

Fix file close at pipeline code generation.

Coverity issue: 380976
Fixes: e3be2495c5 ("net/softnic: add pipeline code generation command")

Signed-off-by: Harshad Narayane <harshad.suresh.narayane@intel.com>
Signed-off-by: Kamalakannan R <kamalakannan.r@intel.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>

drivers/net/softnic/rte_eth_softnic_cli.c

@@ -230,6 +230,7 @@ cmd_softnic_pipeline_codegen(struct pmd_internals *softnic __rte_unused,
 	code_file = fopen(tokens[3], "w");
 	if (!code_file) {
 		snprintf(out, out_size, "Cannot open file %s.\n", tokens[3]);
+		fclose(spec_file);
 		return;
 	}