rtl8192cu: fix build error (vmalloc/vfree undefined)

On the ARM system, a build fails due to missing include.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rtlwifi/rtl8192cu/sw.c b/drivers/net/wireless/rtlwifi/rtl8192cu/sw.c
index 4e937e0..62604cb 100644
--- a/drivers/net/wireless/rtlwifi/rtl8192cu/sw.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192cu/sw.c
@@ -40,7 +40,7 @@
 #include "trx.h"
 #include "led.h"
 #include "hw.h"
-
+#include <linux/vmalloc.h>
 
 MODULE_AUTHOR("Georgia		<georgia@realtek.com>");
 MODULE_AUTHOR("Ziv Huang	<ziv_huang@realtek.com>");