Oops. Fix make variable name. Thanks again, make.

Change-Id: Iecbb41acc835bb8eb20b668c89a3ff065470fcb7
diff --git a/adb/Android.mk b/adb/Android.mk
index 6d18d26..e5bc539 100644
--- a/adb/Android.mk
+++ b/adb/Android.mk
@@ -22,8 +22,8 @@
     transport.c \
     transport_usb.c \
 
-LIBADB_C_FLAGS := \
-    -Wall -Werror \
+LIBADB_CFLAGS := \
+    -Wall -Werror -Wno-unused-parameter \
     -D_XOPEN_SOURCE -D_GNU_SOURCE \
     -fvisibility=hidden \