bnxt_en: Refactor bnxt_get_module_eeprom_by_page()

bnxt_en: Refactor bnxt_get_module_eeprom_by_page()

In preparation for adding .set_module_eeprom_by_page(), extract the
common error checking done in bnxt_get_module_eeprom_by_page() into
a new common function that can be re-used for
.set_module_eeprom_by_page().

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20250310183129.3154117-7-michael.chan@broadcom.com
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>