(read_makefile): Fix `override define' parsing to skip whitespace after

`define' properly.

read.c

@@ -434,7 +434,7 @@ read_makefile (filename, flags)
 		in_ignored_define = 1;
 	      else
 		{
-		  p2 = end_of_token (p2);
+		  p2 = next_token (p2 + 6);
 		  /* Let the variable name be the whole rest of the line,
 		     with trailing blanks stripped (comments have already been
 		     removed), so it could be a complex variable/function