[4.1] b9a817a Remove unneeded checks

[Lasse Karstensen]

commit b9a817aeb4705d7b6d557d334eb899ba1ff89485
Author: Federico G. Schwindt <fgsch at lodoss.net>
Date:   Mon May 16 18:37:44 2016 +0100

    Remove unneeded checks

diff --git a/configure.ac b/configure.ac
index 60ca42d..f506ed5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -239,9 +239,6 @@ AC_CHECK_FUNCS([strerror])
 AC_FUNC_STRERROR_R
 AC_CHECK_FUNCS([dladdr])
 AC_CHECK_FUNCS([socket])
-AC_CHECK_FUNCS([strptime])
-AC_CHECK_FUNCS([fmtcheck])
-AC_CHECK_FUNCS([getdtablesize])
 AC_CHECK_FUNCS([nanosleep])
 AC_CHECK_FUNCS([setppriv])
 AC_CHECK_FUNCS([fallocate])