usb-storage: Use const to reduce object data size

usb-storage: Use const to reduce object data size

Make structs const to reduce data size ~20KB.

Change function arguments and prototypes as necessary to compile.

$ size (x86-64 defconfig pre)
   text	   data	    bss	    dec	    hex	filename
  12281	  10948	    480	  23709	   5c9d	./drivers/usb/storage/usb.o
    111	  10528	      8	  10647	   2997	./drivers/usb/storage/usual-tables.o

$ size (x86-64 defconfig post)
   text	   data	    bss	    dec	    hex	filename
  22809	    420	    480	  23709	   5c9d	drivers/usb/storage/usb.o
  10551	      0	      0	  10551	   2937	drivers/usb/storage/usual-tables.o

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/cf13bd2d790ae3afbf5da55ea7bed12e00c5119d.camel@perches.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>