anv: anv_entrypoints_gen.py: directly write files instead of piping

This changes the output to be written as a file rather than being piped.
This had one critical advantage, it encapsulates the encoding. This
prevents bugs where a symbol (generally unicode like © [copyright]) is
printed and the system being built on doesn't have a unicode locale.

v2: - Update Android.mk
v3: - Don't generate both files at once
    - Fix Android.mk
    - drop --outdir, since the filename is passed in as an argument

Signed-off-by: Dylan Baker <dylanx.c.baker@intel.com>

src/intel/Android.vulkan.mk

@@ -59,7 +59,8 @@ $(intermediates)/vulkan/dummy.c:
 	$(hide) touch $@
 
 $(intermediates)/vulkan/anv_entrypoints.h:
-	$(VK_ENTRYPOINTS_SCRIPT) header --xml $(MESA_TOP)/src/vulkan/registry/vk.xml > $@
+	$(VK_ENTRYPOINTS_SCRIPT) header $@ --xml $(MESA_TOP)/src/vulkan/registry/vk.xml
+
 
 LOCAL_EXPORT_C_INCLUDE_DIRS := \
         $(intermediates)
@@ -179,7 +180,7 @@ LOCAL_WHOLE_STATIC_LIBRARIES := \
 LOCAL_GENERATED_SOURCES += $(intermediates)/vulkan/anv_entrypoints.c
 
 $(intermediates)/vulkan/anv_entrypoints.c:
-	$(VK_ENTRYPOINTS_SCRIPT) code --xml $(MESA_TOP)/src/vulkan/registry/vk.xml > $@
+	$(VK_ENTRYPOINTS_SCRIPT) code $@ --xml $(MESA_TOP)/src/vulkan/registry/vk.xml
 
 LOCAL_SHARED_LIBRARIES := libdrm_intel