tools/Unix.mk: add nuttx.asm to manifest

Fix bug where "nuttx.bin" was written to nuttx.asm instead of appending
nuttx.asm to nuttx.manifest

Signed-off-by: Antoine Juckler <ajuckler@users.noreply.github.com>

Author: ajuckler

tools/Unix.mk

@@ -602,7 +602,7 @@ endif
 ifeq ($(CONFIG_RAW_DISASSEMBLY),y)
 	@echo "CP: nuttx.asm"
 	$(Q) $(OBJDUMP) -d $(BIN) > nuttx.asm
-	$(Q) echo nuttx.bin >> nuttx.asm
+	$(Q) echo nuttx.asm >> nuttx.manifest
 endif
 	$(call POSTBUILD, $(TOPDIR))