tests: execute check-config.py without xargs Before this patch, test-check-config.t fails on Solaris, because "xargs" doesn't invoke check-config.py with all filenames at once. "xargs" may invoke specified command multiple times with part of arguments given from stdin: according to "xargs(1)" man page, this dividing arguments is system-dependent. For portability of test-check-config.t, this patch adds "xargs" like mode to check-config.py and executes it in test-check-config.t without "xargs".