Add prefixes to MSC enumerators, otherwise they are (ERROR) are
conflicting with other enumerators.
...
subsys/usb/class/mass_storage.c:149:2: error: redeclaration of
enumerator ‘ERROR’
ERROR, /* error */
^~~~~
...
ext/hal/st/stm32cube/stm32f4xx/soc/stm32f4xx.h:216:3: note: previous
definition of ‘ERROR’ was here
ERROR = 0U,
^~~~~
...
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>