tools/build: Don't pass test log files to linker

Separate test log files from object files. Depend on test log output
but don't pass to the linker.

Reviewed-by: James Clark <[e-mail]>
Signed-off-by: Ian Rogers <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/build/Makefile.build

···
 obj-y        := $(addprefix $(objprefix),$(obj-y))
 subdir-obj-y := $(addprefix $(objprefix),$(subdir-obj-y))
 
+# Separate out test log files from real build objects.
+test-y       := $(filter %_log, $(obj-y))
+obj-y        := $(filter-out %_log, $(obj-y))
+
 # Final '$(obj)-in.o' object
 in-target := $(objprefix)$(obj)-in.o
 
···
 
 $(sort $(subdir-obj-y)): $(subdir-y) ;
 
-$(in-target): $(obj-y) FORCE
+$(in-target): $(obj-y) $(test-y) FORCE
 	$(call rule_mkdir)
 	$(call if_changed,$(host)ld_multi)