MFC r247268:
 Several cleanups and fixes to mxge:

 - Remove vestigial null pointer tests after malloc(..., M_WAITOK).

 - Remove vestigal qualhack union

 - Use strlcpy() instead of the error-prone strncpy() when parsing
   EEPROM and copying strings

 - Check the MAC address in the EEPROM strings more strictly.

 - Expand the macro MXGE_NEXT_STRING() at its only user. Due to a typo,
   the macro was very confusing.

 - Remove unnecessary buffer limit check.  The buffer is double-NUL
   terminated per construction.

PR:             kern/176369
Submitted by:   Christoph Mallon <christoph.mallon gmx.de>