(gl_XNANOSLEEP): Remove configuration attempting

to detect nanosleep bug.

m4/xnanosleep.m4

@@ -1,4 +1,4 @@
-# xnanosleep.m4 serial 1
+# xnanosleep.m4 serial 2
 dnl Copyright (C) 2005 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -10,26 +10,4 @@ AC_DEFUN([gl_XNANOSLEEP],
 [
   AC_LIBSOURCES([xnanosleep.c, xnanosleep.h])
   AC_LIBOBJ([xnanosleep])
-
-  dnl Prerequisites of lib/xnanosleep.c.
-  AC_REQUIRE([gl_PREREQ_GETHRXTIME])
-
-  LIB_XNANOSLEEP=
-  case $LIB_GETHRXTIME in
-  ?*)
-    AC_CACHE_CHECK([whether __linux__ is defined],
-      gl_cv_have___linux__,
-      [AC_EGREP_CPP([have___linux__],
-	[
-#        ifdef __linux__
-	  have___linux__
-#        endif
-	],
-	gl_cv_have___linux__=yes,
-	gl_cv_have___linux__=no)])
-    if test $gl_cv_have___linux__ = yes; then
-      LIB_XNANOSLEEP=$LIB_GETHRXTIME
-    fi;;
-  esac
-  AC_SUBST([LIB_XNANOSLEEP])
 ])