fastboot: Fix fastboot reboot fail by changing functions order

It was revealed that when the fastboot_tx_write_str function is called
without the previously initialized fastboot_func->in_req->complete field,
a copy of in_req will be sent to the I/O requests queue without
an initialized field.

Moving a piece of code with the initializing of the
fastboot_func->in_req->complete field above transmit_tx allows to solve
this problem.

Fixes: 65c96757fe9 "usb: fastboot: Convert USB f_fastboot to shared fastboot"
Signed-off-by: yurii.pidhornyi <yurii.pidhornyi@globallogic.com>
diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
index 30f7a52..d1d087e 100644
--- a/drivers/usb/gadget/f_fastboot.c
+++ b/drivers/usb/gadget/f_fastboot.c
@@ -441,8 +441,6 @@
 		req->length = rx_bytes_expected(ep);
 	}
 
-	fastboot_tx_write_str(response);
-
 	if (!strncmp("OKAY", response, 4)) {
 		switch (cmd) {
 		case FASTBOOT_COMMAND_BOOT:
@@ -462,6 +460,8 @@
 		}
 	}
 
+	fastboot_tx_write_str(response);
+
 	*cmdbuf = '\0';
 	req->actual = 0;
 	usb_ep_queue(ep, req, 0);