Use common makefile style.

Also remove an extra parenthese that shouldn't have been there.

Change-Id: I821c7591afe1c66aaa3275273d09cd37f03ff63c
diff --git a/self-extractors/nvidia/staging/keymaster/Android.mk b/self-extractors/nvidia/staging/keymaster/Android.mk
index 9695ca4..43c0f5e 100644
--- a/self-extractors/nvidia/staging/keymaster/Android.mk
+++ b/self-extractors/nvidia/staging/keymaster/Android.mk
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 ifeq ($(TARGET_ARCH),arm)
-ifeq (tilapia,$(TARGET_DEVICE)))
+ifeq ($(TARGET_DEVICE),tilapia)
 
 LOCAL_PATH := $(call my-dir)