UBI: block: Mark init-only symbol as __initdata

ubiblock_param_ops should be marked as __init as it's only used to set
a driver parameter on insertion time. This commit fixes the following:

  WARNING: drivers/mtd/built-in.o(.text+0x653ac): Section mismatch in
  reference from the variable ubiblock_param_ops to the function
  .init.text:ubiblock_set_param()

  The function ubiblock_param_ops() references the function __init
  ubiblock_set_param(). This is often because ubiblock_param_ops lacks a
  __init annotation or the annotation of ubiblock_set_param is wrong.

Given gcc errors if the struct is marked const __initdata, this commit
drops the const mark from it.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

drivers/mtd/ubi/block.c

@@ -156,7 +156,7 @@ static int __init ubiblock_set_param(const char *val,
 	return 0;
 }
 
-static const struct kernel_param_ops ubiblock_param_ops = {
+static struct kernel_param_ops ubiblock_param_ops __initdata = {
 	.set    = ubiblock_set_param,
 };
 module_param_cb(block, &ubiblock_param_ops, NULL, 0);