tests/data/Makefile: remove 'filecheck' target

No practical use anymore since 3c0f462

Closes curl#9332

tests/data/Makefile.am

@@ -29,21 +29,3 @@ test:
 include Makefile.inc
 
 EXTRA_DIST = $(TESTCASES) DISABLED CMakeLists.txt
-
-filecheck:
-	@mkdir test-place; \
-	cp "$(top_srcdir)"/tests/data/test[0-9]* test-place/; \
-	rm -f test-place/*~; \
-	for f in $(EXTRA_DIST); do \
-	  if test -f "$(top_srcdir)/tests/data/$$f"; then \
-	    rm -f "test-place/$$f"; \
-	  else \
-	    echo "$$f is listed but missing!"; \
-	  fi \
-	done; \
-	echo "Local files not present in EXTRA_DIST:" ; \
-	ls test-place; \
-	! ls test-place | grep . >/dev/null ; \
-	RC=$$? ; \
-	rm -rf test-place ; \
-	exit $$RC