build: cleanup AX_CHECK_PREPROC_FLAG() usage

There should be no functional change.

Author: fanquake

configure.ac

@@ -364,9 +364,9 @@ if test "x$enable_debug" = xyes; then
     [AX_CHECK_COMPILE_FLAG([-g], [DEBUG_CXXFLAGS="$DEBUG_CXXFLAGS -g"], [], [$CXXFLAG_WERROR])],
     [$CXXFLAG_WERROR])
 
-  AX_CHECK_PREPROC_FLAG([-DDEBUG],[[DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DDEBUG"]],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_PREPROC_FLAG([-DDEBUG_LOCKORDER],[[DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DDEBUG_LOCKORDER"]],,[[$CXXFLAG_WERROR]])
-  AX_CHECK_PREPROC_FLAG([-DABORT_ON_FAILED_ASSUME],[[DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DABORT_ON_FAILED_ASSUME"]],,[[$CXXFLAG_WERROR]])
+  AX_CHECK_PREPROC_FLAG([-DDEBUG], [DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DDEBUG"], [], [$CXXFLAG_WERROR])
+  AX_CHECK_PREPROC_FLAG([-DDEBUG_LOCKORDER], [DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DDEBUG_LOCKORDER"], [], [$CXXFLAG_WERROR])
+  AX_CHECK_PREPROC_FLAG([-DABORT_ON_FAILED_ASSUME], [DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DABORT_ON_FAILED_ASSUME"], [], [$CXXFLAG_WERROR])
   AX_CHECK_COMPILE_FLAG([-ftrapv], [DEBUG_CXXFLAGS="$DEBUG_CXXFLAGS -ftrapv"], [], [$CXXFLAG_WERROR])
 fi
 
@@ -1270,7 +1270,7 @@ if test "x$enable_fuzz" = "xyes"; then
   use_zmq=no
   enable_fuzz_binary=yes
 
-  AX_CHECK_PREPROC_FLAG([-DABORT_ON_FAILED_ASSUME],[[DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DABORT_ON_FAILED_ASSUME"]],,[[$CXXFLAG_WERROR]])
+  AX_CHECK_PREPROC_FLAG([-DABORT_ON_FAILED_ASSUME], [DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DABORT_ON_FAILED_ASSUME"], [], [$CXXFLAG_WERROR])
 
   AC_MSG_CHECKING([whether main function is needed for fuzz binary])
   AX_CHECK_LINK_FLAG(
@@ -1613,7 +1613,7 @@ if test "x$use_ccache" != "xno"; then
   AC_MSG_RESULT($use_ccache)
   if test "x$use_ccache" = "xyes"; then
     AX_CHECK_COMPILE_FLAG([-fdebug-prefix-map=A=B], [DEBUG_CXXFLAGS="$DEBUG_CXXFLAGS -fdebug-prefix-map=\$(abs_top_srcdir)=."], [], [$CXXFLAG_WERROR])
-    AX_CHECK_PREPROC_FLAG([-fmacro-prefix-map=A=B],[DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -fmacro-prefix-map=\$(abs_top_srcdir)=."],,[[$CXXFLAG_WERROR]])
+    AX_CHECK_PREPROC_FLAG([-fmacro-prefix-map=A=B], [DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -fmacro-prefix-map=\$(abs_top_srcdir)=."], [], [$CXXFLAG_WERROR])
   fi
 fi