corex: close fd if ftell() fails inside file_read()

src/modules/corex/corex_mod.c

@@ -343,6 +343,7 @@ static int w_file_read(sip_msg_t *msg, char *fn, char *vn)
 	fsize = ftell(f);
 	if(fsize<0) {
 		LM_ERR("ftell failed on file: %.*s\n", fname.len, fname.s);
+		fclose(f);
 		return -1;
 	}
 	fseek(f, 0, SEEK_SET);