Bump kldxref's MAXSEGS to 16, to stop complaints about the kernel

supposedly having too many segments, when lld 11 links it. Such kernels
should load just fine.

Note that we may still do some tweaking of our kernel linker scripts, to
lower the number of segments, although the exact benefit is not entirely
clear.

usr.sbin/kldxref/ef.c

@@ -49,7 +49,7 @@
 
 #include "ef.h"
 
-#define	MAXSEGS 3
+#define	MAXSEGS 16
 struct ef_file {
 	char		*ef_name;
 	struct elf_file *ef_efile;