Fix flash probing by name. Flash entries without a name are allowed
since commit 15eb8303 ("mtd: spi-nor: mark the flash name as
obsolete"). But it was just until recently that a flash entry without a
name was actually introduced. This triggers a bug in the legacy probe by
name path. Skip entries without a name to fix it.

Fixes: 2095e7da8049 ("mtd: spi-nor: spansion: Add support for S28HS256T")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Closes: https://lore.kernel.org/r/66c8ebb0-1324-4ad9-9926-8d4eb7e1e63a@nvidia.com/Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Link: https://lore.kernel.org/r/20240909072854.812206-1-mwalle@kernel.org