make: fix GCC warnings

*** 28,38 ****
  
  #include <stdio.h>
  
  extern FILE     *get_report_file(void);
  extern char     *get_target_being_reported_for(void);
! extern void     report_dependency(register char *name);
  extern int      file_lock(char *name, char *lockname, int *file_locked, int timeout);
  #ifdef NSE
  extern char     *setenv(char *name, char *value);
  #endif
  
--- 28,38 ----
  
  #include <stdio.h>
  
  extern FILE     *get_report_file(void);
  extern char     *get_target_being_reported_for(void);
! extern void     report_dependency(const char *name);
  extern int      file_lock(char *name, char *lockname, int *file_locked, int timeout);
  #ifdef NSE
  extern char     *setenv(char *name, char *value);
  #endif