Remove conflicting declarations.

darwin/Platform.c

@@ -81,7 +81,6 @@ void Platform_setBindings(Htop_Action* keys) {
 }
 
 int Platform_numberOfFields = 100;
-char* Process_pidFormat = "%7u ";
 
 int Platform_getUptime() {
    struct timeval bootTime, currTime;

darwin/Platform.h

@@ -23,7 +23,6 @@ extern MeterClass* Platform_meterTypes[];
 void Platform_setBindings(Htop_Action* keys);
 
 extern int Platform_numberOfFields;
-extern char* Process_pidFormat;
 
 int Platform_getUptime();