Ensure -NDEBUG does not get added to spl_config.h and is only set in the build options. This allows other kernel modules to use spl_config to leverage the reset of the config checks without getting confused with the debug options

config/spl-build.m4

@@ -97,8 +97,6 @@ AC_DEFUN([SPL_AC_DEBUG], [
 		KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG"
 	else
 		AC_MSG_RESULT([no])
-		AC_DEFINE([NDEBUG], [1],
-		[Define to 1 to disable debug tracing])
 		KERNELCPPFLAGS="${KERNELCPPFLAGS} -DNDEBUG"
 	fi
 ])

configure

@@ -19046,11 +19046,6 @@ echo "${ECHO_T}yes" >&6
 	else
 		echo "$as_me:$LINENO: result: no" >&5
 echo "${ECHO_T}no" >&6
-
-cat >>confdefs.h <<\_ACEOF
-#define NDEBUG 1
-_ACEOF
-
 		KERNELCPPFLAGS="${KERNELCPPFLAGS} -DNDEBUG"
 	fi
 

module/spl/spl-debug.c

@@ -1118,10 +1118,8 @@ void spl_debug_bug(char *file, const char *func, const int line, int flags)
          if (spl_debug_panic_on_bug)
                 spl_panic_in_progress = 1;
 
-#ifdef DEBUG
         spl_debug_dumpstack(NULL);
         spl_debug_dumplog(flags);
-#endif
 
         if (spl_debug_panic_on_bug)
                 panic("SBUG");

spl_config.h.in

@@ -108,9 +108,6 @@
 /* Define to 1 if you have the <unistd.h> header file. */
 #undef HAVE_UNISTD_H
 
-/* Define to 1 to disable debug tracing */
-#undef NDEBUG
-
 /* Name of package */
 #undef PACKAGE