include: Switch to #pragma once pattern

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/include/osmocom/gprs/gprs_ns.h b/include/osmocom/gprs/gprs_ns.h
index 296800e..b4af61b 100644
--- a/include/osmocom/gprs/gprs_ns.h
+++ b/include/osmocom/gprs/gprs_ns.h
@@ -1,5 +1,4 @@
-#ifndef _GPRS_NS_H
-#define _GPRS_NS_H
+#pragma once
 
 #include <stdint.h>
 
@@ -215,5 +214,3 @@
 void gprs_ns_set_log_ss(int ss);
 
 /*! }@ */
-
-#endif