Fix kernelmemfs linking

Commit 9aa0337d introduced a linker script for linking the kernel image,
but only changed the kernel target to use it.  kernelmemfs was still
using the old linker command line arguments, which weren't sufficient.

Makefile

@@ -124,7 +124,7 @@ kernel: $(OBJS) entry.o entryother initcode kernel.ld
 # needing a scratch disk.
 MEMFSOBJS = $(filter-out ide.o,$(OBJS)) memide.o
 kernelmemfs: $(MEMFSOBJS) entry.o entryother initcode fs.img
-	$(LD) $(LDFLAGS) -Ttext 0x100000 -e main -o kernelmemfs entry.o  $(MEMFSOBJS) -b binary initcode entryother fs.img
+	$(LD) $(LDFLAGS) -T kernel.ld -o kernelmemfs entry.o  $(MEMFSOBJS) -b binary initcode entryother fs.img
 	$(OBJDUMP) -S kernelmemfs > kernelmemfs.asm
 	$(OBJDUMP) -t kernelmemfs | sed '1,/SYMBOL TABLE/d; s/ .* / /; /^$$/d' > kernelmemfs.sym