lguest: clean up warnings in demonstration launcher.

These days the headers we use are in glibc.  If those are too old, you can
add the -I lines to get the kernel headers.

In file included from ../../include/linux/if_tun.h:19,
                 from lguest.c:33:
../../include/linux/types.h:13:2: warning: #warning "Attempt to use kernel headers from user space, see http://kernelnewbies.org/KernelHeaders"
lguest.c: In function ‘setup_tun_net’:
lguest.c:1456: warning: dereferencing pointer ‘sin’ does break strict-aliasing rules
lguest.c:1457: warning: dereferencing pointer ‘sin’ does break strict-aliasing rules
lguest.c:1450: note: initialized from here

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/Documentation/lguest/Makefile b/Documentation/lguest/Makefile
index 28c8cdf..bebac6b 100644
--- a/Documentation/lguest/Makefile
+++ b/Documentation/lguest/Makefile
@@ -1,5 +1,6 @@
 # This creates the demonstration utility "lguest" which runs a Linux guest.
-CFLAGS:=-m32 -Wall -Wmissing-declarations -Wmissing-prototypes -O3 -I../../include -I../../arch/x86/include -U_FORTIFY_SOURCE
+# Missing headers?  Add "-I../../include -I../../arch/x86/include"
+CFLAGS:=-m32 -Wall -Wmissing-declarations -Wmissing-prototypes -O3 -U_FORTIFY_SOURCE
 
 all: lguest