Staging: ft1000-usb: Fix Smatch Warning in ft1000_hw.c

This patch fixes following smatch warning:
/drivers/staging/ft1000/ft1000-usb/ft1000_hw.c:1148 ft1000_proc_drvmsg() warn: returning -1 instead of -ENOMEM is sloppy
Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>

drivers/staging/ft1000/ft1000-usb/ft1000_hw.c

@@ -1145,7 +1145,7 @@ static int ft1000_proc_drvmsg(struct ft1000_usb *dev, u16 size)
 
 	char *cmdbuffer = kmalloc(1600, GFP_KERNEL);
 	if (!cmdbuffer)
-		return -1;
+		return -ENOMEM;
 
 	status = ft1000_read_dpram32(dev, 0x200, cmdbuffer, size);