Add liblog dependency to libbt-vendor.

lubcutils doesn't bundle liblog anymore. This fixes the build in boards
defining BOARD_HAVE_BLUETOOTH_LINUX.

Bug: None
Test: `make droid` in such board.
Change-Id: Ic9b7ba045c3a291eb33a606ffabc41c45c9ca3e2

system/vendor_libs/linux/Android.mk

@@ -31,6 +31,7 @@ LOCAL_C_INCLUDES := \
         $(LOCAL_PATH)/../../
 
 LOCAL_SHARED_LIBRARIES := \
+        liblog \
         libcutils
 
 LOCAL_STATIC_LIBRARIES := libosi