fix to successfully build and test with --disable-gst-debug configure switch

fix to successfully build and test with --disable-gst-debug configure switch

Original commit message from CVS:
* gst/autoplug/gstspider.c: (gst_spider_identity_plug):
* gst/gstinfo.h:
* testsuite/debug/category.c: (main):
* testsuite/debug/commandline.c: (main):
* testsuite/debug/output.c: (main):
* testsuite/debug/printf_extension.c: (main):
fix to successfully build and test with --disable-gst-debug
configure switch