Clean include paths of external dependency

This way, LOVE Android.mk doesn't have to be modified in case new libraries
added or in case old libraries gets updated and their name is different.

love/src/jni/mpg123-1.17.0/Android.mk

@@ -7,9 +7,8 @@ LOCAL_MODULE    := libmpg123
 LOCAL_CFLAGS    := -fexceptions -g -Dlinux -DHAVE_GCC_DESTRUCTOR=1 -DOPT_GENERIC -DREAL_IS_FLOAT
 LOCAL_CPPFLAGS  := ${LOCAL_CFLAGS}
 
-LOCAL_C_INCLUDES  :=  \
-	${LOCAL_PATH}/src
-
+LOCAL_C_INCLUDES := ${LOCAL_PATH}/src
+LOCLA_EXPORT_C_INCLUDES := ${LOCAL_C_INCLUDES}
 LOCAL_SRC_FILES := \
 	$(filter-out \
 	  src/libmpg123/dct64_altivec.c \