iax2-provision: Fix improper return on failed cache retrieval

(closes issue ASTERISK-20337)
reported by: John Covert
Patches:
    iax2-provision.c.patch uploaded by John Covert (license 5512)
........

Merged revisions 373342 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 373343 from http://svn.asterisk.org/svn/asterisk/branches/10
........

Merged revisions 373368 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@373369 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/iax2-provision.c

@@ -262,10 +262,8 @@ int iax_provision_version(unsigned int *version, const char *template, int force
 	memset(&ied, 0, sizeof(ied));
 
 	ast_mutex_lock(&provlock);
-	if (!(ast_db_get("iax/provisioning/cache", template, tmp, sizeof(tmp)))) {
-		ast_log(LOG_ERROR, "ast_db_get failed to retrieve iax/provisioning/cache\n");
-		ast_mutex_unlock(&provlock);
-		return -1;
+	if (ast_db_get("iax/provisioning/cache", template, tmp, sizeof(tmp))) {
+		ast_log(LOG_ERROR, "ast_db_get failed to retrieve iax/provisioning/cache/%s\n", template);
 	}
 	if (sscanf(tmp, "v%30x", version) != 1) {
 		if (strcmp(tmp, "u")) {