dmx_usb_module: fix compilation warning

Fix compilation warning due to wrong cast.
In file included from ./include/linux/kernel.h:19,
                 from /home/ansuel/openwrt-ansuel/openwrt/build_dir/target-aarch64_cortex-a53_musl/linux-ipq807x_generic/dmx_usb_module-19.12.1/dmx_usb.c:16:
/home/ansuel/openwrt-ansuel/openwrt/build_dir/target-aarch64_cortex-a53_musl/linux-ipq807x_generic/dmx_usb_module-19.12.1/dmx_usb.c: In function 'dmx_usb_write':
./include/linux/kern_levels.h:5:25: error: format '%d' expects argument of type 'int', but argument 4 has type 'size_t' {aka 'long unsigned int'} [-Werror=format=]
    5 | #define KERN_SOH        "\001"          /* ASCII Start Of Header */
      |                         ^~~~~~
./include/linux/printk.h:422:25: note: in definition of macro 'printk_index_wrap'
  422 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
      |                         ^~~~
/home/ansuel/openwrt-ansuel/openwrt/build_dir/target-aarch64_cortex-a53_musl/linux-ipq807x_generic/dmx_usb_module-19.12.1/dmx_usb.c:41:45: note: in expansion of macro 'printk'
   41 | #define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg); } while (0)
      |                                             ^~~~~~
./include/linux/kern_levels.h:15:25: note: in expansion of macro 'KERN_SOH'
   15 | #define KERN_DEBUG      KERN_SOH "7"    /* debug-level messages */
      |                         ^~~~~~~~
/home/ansuel/openwrt-ansuel/openwrt/build_dir/target-aarch64_cortex-a53_musl/linux-ipq807x_generic/dmx_usb_module-19.12.1/dmx_usb.c:41:52: note: in expansion of macro 'KERN_DEBUG'
   41 | #define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg); } while (0)
      |                                                    ^~~~~~~~~~
/home/ansuel/openwrt-ansuel/openwrt/build_dir/target-aarch64_cortex-a53_musl/linux-ipq807x_generic/dmx_usb_module-19.12.1/dmx_usb.c:409:9: note: in expansion of macro 'dbg'
  409 |         dbg("%s - minor %d, count = %d", __FUNCTION__, dev->minor, count);
      |         ^~~
cc1: all warnings being treated as errors

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

diff --git a/libs/dmx_usb_module/patches/100-fix-compilation-warning-wrong-cast.patch b/libs/dmx_usb_module/patches/100-fix-compilation-warning-wrong-cast.patch
new file mode 100644 (file)
index 0000000..413cb63
--- /dev/null
+++ b/libs/dmx_usb_module/patches/100-fix-compilation-warning-wrong-cast.patch
@@ -0,0 +1,11 @@
+--- a/dmx_usb.c
++++ b/dmx_usb.c
+@@ -406,7 +406,7 @@ static ssize_t dmx_usb_write (struct file *file, const char *buffer, size_t coun
+ 
+       dev = (struct dmx_usb_device *)file->private_data;
+ 
+-      dbg("%s - minor %d, count = %d", __FUNCTION__, dev->minor, count);
++      dbg("%s - minor %d, count = %zu", __FUNCTION__, dev->minor, count);
+ 
+       /* lock this object */
+       down (&dev->sem);