cmd_process warning

[Sergei Antonov]

Hello!
There is an annoying warning about conflicting return types:

common/command.c:586:20: warning: conflicting types for 'cmd_process'
due to enum/integer mismatch; have 'enum command_ret_t(int,  int,
char * const*, int *, ulong *)' {aka 'enum command_ret_t(int,  int,
char * const*, int *, long unsigned int *)'} [-Wenum-int-mismatch]
In file included from common/command.c:13:
include/command.h:234:5: note: previous declaration of 'cmd_process'
with type 'int(int,  int,  char * const*, int *, long unsigned int *)'

It can be fixed by replacing 'int' with 'enum command_ret_t' in
include/command.h