include: Switch to #pragma once pattern

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/include/osmocom/gsm/comp128.h b/include/osmocom/gsm/comp128.h
index e4587d4..33b997a 100644
--- a/include/osmocom/gsm/comp128.h
+++ b/include/osmocom/gsm/comp128.h
@@ -4,8 +4,7 @@
  * See comp128.c for details
  */
 
-#ifndef __COMP128_H__
-#define __COMP128_H__
+#pragma once
 
 #include <stdint.h>
 
@@ -17,6 +16,3 @@
  * kc    : uint8_t [8]
  */
 void comp128(const uint8_t *ki, const uint8_t *srand, uint8_t *sres, uint8_t *kc);
-
-#endif /* __COMP128_H__ */
-