Really move definition of SCSIBUFFERSIZE from CFLAGS to config.h.

(forgot part of the patch last time.)

configure.in

@@ -229,7 +229,8 @@ AC_ARG_ENABLE(scsibuffersize,
   [  --enable-scsibuffersize=N  specify the default size (in bytes) of the buffer
                           for SCSI commands [default=131072]],
   [set_scsibuffersize="$enableval"], [set_scsibuffersize=131072])
-CFLAGS="$CFLAGS -DSCSIBUFFERSIZE=$set_scsibuffersize"
+AC_DEFINE_UNQUOTED(SCSIBUFFERSIZE, $set_scsibuffersize,
+                   [SCSI command buffer size])
 echo "scsi buffersize: $set_scsibuffersize"
 
 AC_SUBST(V_MAJOR)