check_procs: Get rid of HAVE_PROC_PID_EXE

Don't check for /proc/pid/exe at compile time, it could be gone in a
build chroot or the like. Checking at runtime (once) is sufficient.

configure.in

@@ -1632,12 +1632,6 @@ if test -n "$ac_cv_proc_meminfo"; then
 	EXTRAS="$EXTRAS check_swap"
 fi
 
-AC_MSG_CHECKING([for /proc/pid/exe])
-if [readlink /proc/$$/exe > /dev/null 2>&1]; then
-    AC_MSG_RESULT([found])
-    AC_DEFINE(HAVE_PROC_PID_EXE,1,[Define if we have /proc/pid/exe])
-fi
-
 AC_PATH_PROG(PATH_TO_DIG,dig)
 AC_ARG_WITH(dig_command,
             ACX_HELP_STRING([--with-dig-command=PATH],

plugins/check_procs.c

@@ -110,7 +110,7 @@ FILE *ps_input = NULL;
 
 static int
 stat_exe (const pid_t pid, struct_stat_t *buf) {
-#if defined(HAVE_PROC_PID_EXE) && defined(HAVE_SYS_STAT_H)
+#ifdef HAVE_SYS_STAT_H
 	char *path;
 	int ret;
 	xasprintf(&path, "/proc/%d/exe", pid);