Fixup autotool stuff

--- configure.in
+++ configure.in
@@ -25,6 +25,7 @@
 AC_CHECK_TYPE(__u16, u_int16_t)
 AC_CHECK_TYPE(__s32, int32_t)
 AC_CHECK_TYPE(__u32, u_int32_t)
+AC_CHECK_TYPE(__u64, u_int64_t)
 AC_CHECK_TYPE(loff_t, unsigned)
 
 dnl Checks for library functions.
--- src/Makefile.am
+++ src/Makefile.am
@@ -27,4 +27,4 @@
 
 LIBS = @LIBS@
 
-CFLAGS += -Wall -g
+AM_CFLAGS = -Wall