tools: hv: fix compiler warnings about major/target_fname

This patch fixes the below warnings with new glibc and gcc:

hv_vss_daemon.c:100:13: warning: In the GNU C Library, "major" is defined
 by <sys/sysmacros.h>. For historical compatibility, it is currently
defined by <sys/types.h> as well, but we plan to  remove this soon.
To use "major", include <sys/sysmacros.h>  directly.

hv_fcopy_daemon.c:42:2: note: 'snprintf' output between 2 and 1040
bytes into a destination of size 260

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>