mtd: spi-nor: sfdp: Fix last erase region marking

The place of spi_nor_region_mark_end() must be moved, because 'i' is
re-used for the index of erase[].

Fixes: b038e8e3 ("mtd: spi-nor: parse SFDP Sector Map Parameter Table")
Cc: stable@vger.kernel.org
Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
[ta: Add Fixes tag and Cc to stable]
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/02ce8d84b7989ebee33382f6494df53778dd508e.1601612872.git.Takahiro.Kuwano@infineon.com