DFU: fix typo in USB strings
diff --git a/firmware/apps/dfu/usb_strings.txt b/firmware/apps/dfu/usb_strings.txt
index bdf2048..8a4facb 100644
--- a/firmware/apps/dfu/usb_strings.txt
+++ b/firmware/apps/dfu/usb_strings.txt
@@ -1,5 +1,5 @@
 sysmocom - s.f.m.c. GmbH
 SIMtrace 2 compatible device
-DFU (Device Firmare Upgrade)
+DFU (Device Firmware Upgrade)
 RAM
 Flash (Application Partition)