msm8998: fix build when no kernel source in tree

Bug: 33556391
Change-Id: I09a8266033da17411b1464e2c40a247da8b7c882
Signed-off-by: Thierry Strudel <tstrudel@google.com>
diff --git a/msm8998/libbt-vendor/Android.mk b/msm8998/libbt-vendor/Android.mk
index 0225fe9..f69700f 100644
--- a/msm8998/libbt-vendor/Android.mk
+++ b/msm8998/libbt-vendor/Android.mk
@@ -47,8 +47,10 @@
         $(TARGET_OUT_HEADERS)/bt/hci_qcomm_init \
         $(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ/usr/include
 
+ifeq ($(TARGET_COMPILE_WITH_MSM_KERNEL),true)
 LOCAL_ADDITIONAL_DEPENDENCIES += \
 $(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ/usr
+endif
 
 ifeq ($(BOARD_HAS_QCA_BT_AR3002), true)
 LOCAL_C_FLAGS := \