Fix uninitialized value

Could happen if the switch statement hit the default.
Was originally this way in ca682973

contribs/pam_slurm_adopt/pam_slurm_adopt.c

@@ -571,7 +571,7 @@ static int _load_cgroup_config()
 PAM_EXTERN int pam_sm_acct_mgmt(pam_handle_t *pamh, int flags
 				__attribute__((unused)), int argc, const char **argv)
 {
-	int retval = PAM_IGNORE, rc, slurmrc, bufsize, user_jobs;
+	int retval = PAM_IGNORE, rc = PAM_IGNORE, slurmrc, bufsize, user_jobs;
 	char *user_name;
 	List steps = NULL;
 	step_loc_t *stepd = NULL;