support: Add FAIL test failure helper

support: Add FAIL test failure helper

Add a FAIL test failure helper analogous to FAIL_RET, that does not
cause the current function to return, providing a standardized way to
report a test failure with a message supplied while permitting the
caller to continue executing, for further reporting, cleaning up, etc.

Update existing test cases that provide a conflicting definition of FAIL
by removing the local FAIL definition and then as follows:

- tst-fortify-syslog: provide a meaningful message in addition to the
  file name already added by <support/check.h>; 'support_record_failure'
  is already called by 'support_print_failure_impl' invoked by the new
  FAIL test failure helper.

- tst-ctype: no update to FAIL calls required, with the name of the file
  and the line number within of the failure site additionally included
  by the new FAIL test failure helper, and error counting plus count
  reporting upon test program termination also already provided by
  'support_record_failure' and 'support_report_failure' respectively,
  called by 'support_print_failure_impl' and 'adjust_exit_status' also
  respectively.  However in a number of places 'printf' is called and
  the error count adjusted by hand, so update these places to make use
  of FAIL instead.  And last but not least adjust the final summary just
  to report completion, with any error count following as reported by
  the test driver.

- test-tgmath2: no update to FAIL calls required, with the name of the
  file of the failure site additionally included by the new FAIL test
  failure helper.  Also there is no need to track the return status by
  hand as any call to FAIL will eventually cause the test case to return
  an unsuccesful exit status regardless of the return status from the
  test function, via a call to 'adjust_exit_status' made by the test
  driver.

Reviewed-by: DJ Delorie <dj@redhat.com>