Output busybox compilation to /tmp

Busybox compilation is stressing vagrant environments running on windows
hosts, so it's better to move the compilation to a local
file system rather than to a shared one.

This is to fix errors that occur on windows hosts during busybox compilation
like "mv: cannot move foo.a.5454 to foo.a: Text file busy"

Change-Id: Ida4375f125b939ca09f06cad4b917061a8dc9a7a
Signed-off-by: Yacov Manevich <[email protected]>

Author: yacovm

busybox/Makefile

@@ -1,7 +1,7 @@
 BUSYBOX_VER=1.25.1
 BUSYBOX_URL=https://www.busybox.net/downloads/busybox-$(BUSYBOX_VER).tar.bz2
 
-OBJDIR=build/busybox-$(BUSYBOX_VER)
+OBJDIR=/tmp/busybox-$(BUSYBOX_VER)
 
 all: $(OBJDIR)/busybox