net: pfe_eth: Fix resoure leak in pfe_spi_flash_init

Fix Coverity issue: RESOURCE_LEAK.
leaked_storage: Variable addr going out of scope leaks the storage it
points to.

Fixes: e0152dbe ("net: pfe_eth: Use spi_flash_read API to access
flash memory")
Signed-off-by: Kuldeep Singh <kuldeep.singh@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>