Silence cast warning.

Process.c

@@ -48,6 +48,7 @@ in the source distribution for its full text.
 #define PROCESS_FLAG_IO 0x0001
 
 typedef enum ProcessFields {
+   NULL_PROCESSFIELD = 0,
    PID = 1,
    COMM = 2,
    STATE = 3,

Process.h

@@ -28,6 +28,7 @@ in the source distribution for its full text.
 #define PROCESS_FLAG_IO 0x0001
 
 typedef enum ProcessFields {
+   NULL_PROCESSFIELD = 0,
    PID = 1,
    COMM = 2,
    STATE = 3,

Settings.c

@@ -159,7 +159,7 @@ static void readFields(ProcessField* fields, int* flags, const char* line) {
          j++;
       }
    }
-   fields[j] = (ProcessField) NULL;
+   fields[j] = NULL_PROCESSFIELD;
    String_freeArray(ids);
 }