Remove #include <malloc.h> , add #include <libgen.h> (#792)

* src/augprint.c: Remove `#include <malloc.h>`

`<malloc.h>` is not present on all platforms (e.g. macOS). `<stdlib.h>`
should be the place to look for `malloc`, and it has already been
`#include`d.

Signed-off-by: Ruoyu Zhong <zhongruoyu@outlook.com>

* src/augprint.c: Add `#include <libgen.h>`

This fixes a segfault with `augprint -h` on some non-GNU platforms. See:
https://manpages.ubuntu.com/manpages/bionic/en/man3/basename.3.html

Signed-off-by: Ruoyu Zhong <zhongruoyu@outlook.com>

Signed-off-by: Ruoyu Zhong <zhongruoyu@outlook.com>

src/augprint.c

@@ -69,7 +69,7 @@
 #include <string.h>
 #include <augeas.h>
 #include <errno.h>
-#include <malloc.h>
+#include <libgen.h>        /* for basename() on FreeBSD and MacOS */
 #include <sys/param.h>     /* for MIN() MAX() */
 #include <unistd.h>
 #include "augprint.h"