host: replace include guards with #pragma once

Author: antoinevg

firmware/common/rad1o/render.h

@@ -7,4 +7,3 @@ void rad1o_setIntFont(const struct FONT_DEF* font);
 int rad1o_getFontHeight(void);
 int rad1o_DoString(int sx, int sy, const char* s);
 int rad1o_DoChar(int sx, int sy, int c);
-

firmware/common/usb_queue.h

@@ -78,4 +78,3 @@ int usb_transfer_schedule_ack(const usb_endpoint_t* const endpoint);
 void usb_queue_init(usb_queue_t* const queue);
 
 void usb_queue_transfer_complete(usb_endpoint_t* const endpoint);
-

host/libhackrf/src/hackrf.h

@@ -21,8 +21,7 @@ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABI
 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-#ifndef __HACKRF_H__
-#define __HACKRF_H__
+#pragma once
 
 #include <stdint.h>
 #include <sys/types.h>
@@ -2389,5 +2388,3 @@ extern ADDAPI int ADDCALL hackrf_radio_write_register(
 #ifdef __cplusplus
 } // __cplusplus defined.
 #endif
-
-#endif /*__HACKRF_H__*/