make libusb.h usable with Watcom

Closes #904

Signed-off-by: Nathan Hjelm <hjelmn@google.com>

libusb/libusb.h

diff --git a/libusb/libusb.h b/libusb/libusb.h
index b0b5106..d2dfa20 100644
--- a/libusb/libusb.h
+++ b/libusb/libusb.h
@@ -904,7 +904,7 @@
 
 /** \ingroup libusb_asyncio
  * Setup packet for control transfers. */
-#if defined(_MSC_VER)
+#if defined(_MSC_VER) || defined(__WATCOMC__)
 #pragma pack(push, 1)
 #endif
 struct libusb_control_setup {
@@ -932,7 +932,7 @@
 	/** Number of bytes to transfer */
 	uint16_t wLength;
 } LIBUSB_PACKED;
-#if defined(_MSC_VER)
+#if defined(_MSC_VER) || defined(__WATCOMC__)
 #pragma pack(pop)
 #endif
 

libusb/version_nano.h

diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index 957a371..1524109 100644
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 11615
+#define LIBUSB_NANO 11617