depends: fix fallback downloads

In some cases, failed downloads wouldn't trigger a fallback download attempt.
Namely, checksum mismatches.

depends/funcs.mk

@@ -19,15 +19,19 @@ define int_get_all_dependencies
 $(sort $(foreach dep,$(2),$(2) $(call int_get_all_dependencies,$(1),$($(dep)_dependencies))))
 endef
 
-define fetch_file
-(test -f $$($(1)_source_dir)/$(4) || \
-  ( mkdir -p $$($(1)_download_dir) && echo Fetching $(1)... && \
-  ( $(build_DOWNLOAD) "$$($(1)_download_dir)/$(4).temp" "$(2)/$(3)" || \
-    $(build_DOWNLOAD) "$$($(1)_download_dir)/$(4).temp" "$(FALLBACK_DOWNLOAD_PATH)/$(3)" ) && \
+define fetch_file_inner
+    ( mkdir -p $$($(1)_download_dir) && echo Fetching $(3) from $(2) && \
+    $(build_DOWNLOAD) "$$($(1)_download_dir)/$(4).temp" "$(2)/$(3)" && \
     echo "$(5)  $$($(1)_download_dir)/$(4).temp" > $$($(1)_download_dir)/.$(4).hash && \
     $(build_SHA256SUM) -c $$($(1)_download_dir)/.$(4).hash && \
     mv $$($(1)_download_dir)/$(4).temp $$($(1)_source_dir)/$(4) && \
-    rm -rf $$($(1)_download_dir) ))
+    rm -rf $$($(1)_download_dir) )
+endef
+
+define fetch_file
+    ( test -f $$($(1)_source_dir)/$(4) || \
+    ( $(call fetch_file_inner,$(1),$(2),$(3),$(4),$(5)) || \
+      $(call fetch_file_inner,$(1),$(FALLBACK_DOWNLOAD_PATH),$(3),$(4),$(5))))
 endef
 
 define int_get_build_recipe_hash