libbcc: remove use of LOCAL_NO_2ND_ARCH

This is the only remaining use of LOCAL_NO_2ND_ARCH in the
tree.  Remove it and replace it with LOCAL_MODULE_TARGET_ARCH.
If LOCAL_MODULE_TARGET_ARCH were not already being used this
would just be:
LOCAL_MODULE_TARGET_ARCH = $(TARGET_$(my_2nd_arch_prefix)ARCH)
Since LOCAL_MODULE_TARGET_ARCH is already being used, use
TARGET_(2ND_)?ARCH to filter LOCAL_MODULE_TARGET_ARCH, and skip
including the build rule if the resulting LOCAL_MODULE_TARGET_ARCH
is empty.

Change-Id: I6d7e4b9f3fab055b37be3c4a3b21446c59cb1183
diff --git a/libbcc.sha1.mk b/libbcc.sha1.mk
index 1eff581..b535588 100644
--- a/libbcc.sha1.mk
+++ b/libbcc.sha1.mk
@@ -39,13 +39,9 @@
 LOCAL_CFLAGS += -D_REENTRANT -DPIC -fPIC
 LOCAL_CFLAGS += -O3 -nodefaultlibs -nostdlib
 
-ifeq ($(my_2nd_arch_prefix),)
-LOCAL_NO_2ND_ARCH := true
-else
-LOCAL_32_BIT_ONLY := true
-endif
+LOCAL_MODULE_TARGET_ARCH := $(filter $(TARGET_$(my_2nd_arch_prefix)ARCH),$(LLVM_SUPPORTED_ARCH))
 
-LOCAL_MODULE_TARGET_ARCH := $(LLVM_SUPPORTED_ARCH)
-
+ifdef LOCAL_MODULE_TARGET_ARCH
 include $(BUILD_SHARED_LIBRARY)
-endif
\ No newline at end of file
+endif
+endif