include: Switch to #pragma once pattern

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/include/osmocom/core/talloc.h b/include/osmocom/core/talloc.h
index f7f7643..dde102b 100644
--- a/include/osmocom/core/talloc.h
+++ b/include/osmocom/core/talloc.h
@@ -1,5 +1,4 @@
-#ifndef _TALLOC_H_
-#define _TALLOC_H_
+#pragma once
 /* 
    Unix SMB/CIFS implementation.
    Samba temporary memory allocation functions
@@ -188,5 +187,3 @@
 char *talloc_asprintf_append_buffer(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
 
 void talloc_set_abort_fn(void (*abort_fn)(const char *reason));
-
-#endif