misc/xilinx_sdfec: Call kunmap() on pages mapped with kmap()

Pages in an array are mapped in a loop but, after the code is done with
the virtual addresses, these pages are never unmapped.

Therefore, call kunmap() to unmap pages[i].

Cc: "Venkataramanan, Anirudh" <anirudh.venkataramanan@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20220901154408.23984-2-fmdefrancesco@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/xilinx_sdfec.c

@@ -645,6 +645,7 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdfec, u32 offset,
 			reg++;
 		} while ((reg < len) &&
 			 ((reg * XSDFEC_REG_WIDTH_JUMP) % PAGE_SIZE));
+		kunmap(pages[i]);
 		unpin_user_page(pages[i]);
 	}
 	return 0;