MLK-15081 usb: gadget: utp: fix build warning with aarch64 compiler

MLK-15081 usb: gadget: utp: fix build warning with aarch64 compiler

Compiler will generate below complain if using %d to print size_t, fix it
by using %zd.

drivers/usb/gadget/function/fsl_updater.c: In function ‘utp_do_read’:
./include/linux/kern_levels.h:4:18: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘size_t {aka long unsigned int}’ [-Wformat=]
 #define KERN_SOH "\001"  /* ASCII Start Of Header */
                  ^
./include/linux/kern_levels.h:13:19: note: in expansion of macro ‘KERN_SOH’
 #define KERN_INFO KERN_SOH "6" /* informational */
                   ^~~~~~~~
./include/linux/printk.h:284:9: note: in expansion of macro ‘KERN_INFO’
  printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
         ^~~~~~~~~
drivers/usb/gadget/function/fsl_updater.c:245:3: note: in expansion of macro ‘pr_info’
   pr_info("Copied to %p, %d bytes started from %d\n",
   ^~~~~~~

Acked-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Li Jun <jun.li@nxp.com>