Replace err != 0 with err != nil where possible

core/prof/spall/spall_linux.odin

@@ -11,20 +11,11 @@ MAX_RW :: 0x7fffffff
 
 @(no_instrumentation)
 _write :: proc "contextless" (fd: os.Handle, data: []byte) -> (n: int, err: os.Error) #no_bounds_check /* bounds check would segfault instrumentation */ {
-	if len(data) == 0 {
-		return 0, nil
-	}
-	
 	for n < len(data) {
 		chunk := data[:min(len(data), MAX_RW)]
-		written, errno := linux.write(linux.Fd(fd), chunk)
-		if errno != nil {
-			return n, os.Platform_Error(errno)
-		}
-		n += written
+		n += linux.write(linux.Fd(fd), chunk) or_return
 	}
-
-	return n, nil
+	return
 }
 
 CLOCK_MONOTONIC_RAW :: 4 // NOTE(tetra): "RAW" means: Not adjusted by NTP.