configure: make --with-test-suite work

Our option '--with-test-suite' could have never worked since it was
defined as AC_ARG_ENABLE([with-test-suite], ...), thus working only as
'--enable-with-test-suite', but documented in configure.ac as
AC_HELP_STRING([--with-test-suite], ...).
In my opinion, the help string is as it should be, but the option is
wrong.

The option has been broken since the introduction in commit 3a2fc277.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

configure.ac

@@ -2035,14 +2035,14 @@ dnl Allow perl/python overrides
 AC_PATH_PROGS([PYTHON], [python2 python])
 AC_PATH_PROG([PERL], [perl])
 
-AC_ARG_ENABLE([with-test-suite],
-              [AS_HELP_STRING([--with-test-suite],
-                 [build test suite by default @<:@default=check@:>@])],
-              [case "${withval}" in
-                 yes|no|check) ;;
-                 *)      AC_MSG_ERROR([bad value ${withval} for tests option]) ;;
-              esac],
-              [withval=check])
+AC_ARG_WITH([test-suite],
+            [AS_HELP_STRING([--with-test-suite],
+               [build test suite by default @<:@default=check@:>@])],
+            [case "${withval}" in
+               yes|no|check) ;;
+               *)      AC_MSG_ERROR([bad value ${withval} for tests option]) ;;
+            esac],
+            [withval=check])
 
 AC_MSG_CHECKING([Whether to build test suite by default])
 if test "$withval" = "check" ; then