serial_test: fix write for max buffer size

src/systemcmds/serial_test/serial_test.c

@@ -574,7 +574,6 @@ static void process_read_data(struct g_mod_t *g_mod, struct cli_args_t *g_cl)
 static void process_write_data(struct g_mod_t *g_mod, struct cli_args_t *g_cl)
 {
 	ssize_t count = 0;
-	int loops = 10;
 	int repeat = (g_cl->_tx_bytes == 0);
 
 	do {
@@ -594,13 +593,11 @@ static void process_write_data(struct g_mod_t *g_mod, struct cli_args_t *g_cl)
 
 			c = 0;
 
-		} else {
-			loops--;
 		}
 
 		count += c;
 
-		if (loops == 0 || c < g_mod->_write_size) {
+		if (c <= g_mod->_write_size) {
 			g_mod->_write_count_value = g_mod->_write_data[c];
 			repeat = 0;
 		}