Use '#pragma once' instead of include guard

The most compilers today do support the '#pragma once', which is
designed to cause the current source file to be included only once
in a single compilation. One has several advantages, including:
less code, avoidance of name clashes, and sometimes improvement
in compilation speed.

See: https://en.wikipedia.org/wiki/Pragma_once for details.

include/gsmhr/gsmhr.h

@@ -17,8 +17,7 @@
  * along with gapk.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __GSM_HR_H__
-#define __GSM_HR_H__
+#pragma once
 
 #include <stdint.h>
 
@@ -36,5 +35,3 @@ int           gsmhr_decode(struct gsmhr *state, int16_t *pcm, const int16_t *hr_
 #ifdef __cplusplus
 }
 #endif
-
-#endif /* __GSM_HR_H__ */

include/osmocom/gapk/benchmark.h

@@ -1,6 +1,3 @@
-#ifndef _BENCHMARK_H
-#define _BENCHMARK_H
-
 /*
  * This file is part of gapk (GSM Audio Pocket Knife).
  *
@@ -20,6 +17,8 @@
  * (C) 2014 Harald Welte <laforge@gnumonks.org>
  */
 
+#pragma once
+
 #include <osmocom/gapk/get_cycles.h>
 #include <osmocom/gapk/codecs.h>
 
@@ -56,5 +55,3 @@ static inline void benchmark_stop(enum codec_type codec, int encode, unsigned lo
 				} while (0)
 
 void benchmark_dump(void);
-
-#endif

include/osmocom/gapk/codecs.h

@@ -17,8 +17,7 @@
  * along with gapk.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __GAPK_CODECS_H__
-#define __GAPK_CODECS_H__
+#pragma once
 
 #include <stdint.h>
 
@@ -67,5 +66,3 @@ struct codec_desc {
 };
 
 const struct codec_desc *codec_get_from_type(enum codec_type type);
-
-#endif /* __GAPK_CODECS_H__ */

include/osmocom/gapk/formats.h

@@ -17,8 +17,7 @@
  * along with gapk.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __GAPK_FORMATS_H__
-#define __GAPK_FORMATS_H__
+#pragma once
 
 #include <stdint.h>
 
@@ -90,5 +89,3 @@ struct format_desc {
 
 const struct format_desc *fmt_get_from_type(enum format_type type);
 const struct format_desc *fmt_get_from_name(const char *name);
-
-#endif /* __GAPK_FORMATS_H__ */

include/osmocom/gapk/get_cycles.h

@@ -33,8 +33,7 @@
  * $Id$
  */
 
-#ifndef GET_CLOCK_H
-#define GET_CLOCK_H
+#pragma once
 
 #if 0
 
@@ -134,5 +133,3 @@ static inline cycles_t get_cycles()
 #endif
 
 extern double get_cpu_mhz(void);
-
-#endif /* GET_CLOCK_H */

include/osmocom/gapk/procqueue.h

@@ -17,8 +17,7 @@
  * along with gapk.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __GAPK_PROCQUEUE_H__
-#define __GAPK_PROCQUEUE_H__
+#pragma once
 
 #include <stdint.h>
 #include <stdio.h> /* for FILE */
@@ -68,5 +67,3 @@ int pq_queue_fmt_convert(struct pq *pq, const struct format_desc *fmt, int to_fr
 /* Codec */
 struct codec_desc;
 int pq_queue_codec(struct pq *pq, const struct codec_desc *codec, int encode);
-
-#endif /* __GAPK_PROCQUEUE_H__ */

include/osmocom/gapk/utils.h

@@ -17,8 +17,7 @@
  * along with gapk.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __GAPK_UTILS_H__
-#define __GAPK_UTILS_H__
+#pragma once
 
 #include <stdint.h>
 
@@ -100,5 +99,3 @@ lsb_clr_bit(uint8_t *buf, int bn)
 
 	buf[pos_byte] &= ~(1 << pos_bit);
 }
-
-#endif /* __GAPK_UTILS_H__ */