Drop redundant declarations

- `CRT_fatalError()` is declared twice in CRT.h
- `Process_pidFormat`, `Process_writeField()` and `Process_compare` are
  declared twice in Process.h
- `btime` is defined in LinuxProcess.c and also declared in
  LinuxProcess.h, so drop in LinuxProcessList.h

CRT.h

@@ -168,8 +168,6 @@ void CRT_init(int delay, int colorScheme, bool allowUnicode);
 
 void CRT_done(void);
 
-void CRT_fatalError(const char* note);
-
 int CRT_readKey(void);
 
 void CRT_disableDelay(void);

Process.h

@@ -148,8 +148,6 @@ typedef struct ProcessClass_ {
 #define ONE_DECIMAL_G (ONE_DECIMAL_M * ONE_DECIMAL_K)
 #define ONE_DECIMAL_T ((long long)ONE_DECIMAL_G * ONE_DECIMAL_K)
 
-extern char Process_pidFormat[20];
-
 void Process_setupColumnWidths(void);
 
 void Process_humanNumber(RichString* str, unsigned long number, bool coloring);
@@ -160,8 +158,6 @@ void Process_printTime(RichString* str, unsigned long long totalHundredths);
 
 void Process_outputRate(RichString* str, char* buffer, int n, double rate, int coloring);
 
-void Process_writeField(Process* this, RichString* str, ProcessField field);
-
 void Process_display(Object* cast, RichString* out);
 
 void Process_done(Process* this);
@@ -180,6 +176,4 @@ bool Process_sendSignal(Process* this, Arg sgn);
 
 long Process_pidCompare(const void* v1, const void* v2);
 
-long Process_compare(const void* v1, const void* v2);
-
 #endif

linux/LinuxProcessList.h

@@ -10,8 +10,6 @@ in the source distribution for its full text.
 #include "ProcessList.h"
 #include "zfs/ZfsArcStats.h"
 
-extern long long btime;
-
 typedef struct CPUData_ {
    unsigned long long int totalTime;
    unsigned long long int userTime;